Dabrafenib and Trametinib for BRAF V600E-Positive Anaplastic Thyroid Cancer

Dabrafenib and trametinib for BRAF V600E-positive anaplastic thyroid cancer have changed the treatment pathway for selected patients with this aggressive disease. This targeted combination can produce significant tumour shrinkage, improve disease control and, in some patients, create an opportunity for surgery that was not possible at diagnosis.

Dabrafenib and trametinib for BRAF V600E–positive anaplastic thyroid cancer have changed how doctors approach a selected group of patients with this aggressive disease. These medicines do not work against every anaplastic thyroid cancer. They are designed specifically for tumours carrying the BRAF V600E mutation, so the mutation must be confirmed before treatment is started [1–3].

Anaplastic thyroid cancer can enlarge rapidly and affect the trachea, oesophagus, voice nerves or major blood vessels in the neck. For this reason, molecular treatment should be planned quickly, but it must not delay emergency care for breathing difficulty, stridor, bleeding or severe swallowing problems. The first priority is always to protect the patient’s airway and stabilise the immediate clinical condition [1].

Why the BRAF V600E Result Can Change the Treatment Plan

BRAF V600E is an abnormal change within the tumour that keeps an important cancer-growth pathway continuously active. Dabrafenib blocks the abnormal BRAF signal, while trametinib blocks MEK, another protein situated further down the same pathway. By blocking the pathway at two points, the combination may slow tumour growth or produce significant tumour shrinkage [3,9,10].

If your biopsy or molecular report confirms BRAF V600E, the result is not simply another laboratory finding. It can immediately influence which systemic treatment is considered, how quickly treatment is started and whether an initially inoperable tumour should later be reassessed for surgery.

The mutation result should still be interpreted as part of the complete clinical picture. The oncology team must also consider the tumour’s location, stage, airway risk, distant spread, swallowing ability, general strength, heart function and whether meaningful surgery or radiation remains possible.

How Much Benefit Can Patients Realistically Expect?

In the FDA-reviewed ATC cohort, 53% of 36 patients achieved an objective tumour response with dabrafenib and trametinib. This included a 6% complete response rate and a 47% partial response rate. Among those who responded, the median duration of response was 13.6 months, although some responses were shorter and others lasted considerably longer [3].

The updated ROAR study similarly found an objective response in approximately 56% of patients with BRAF V600E–mutated ATC [10]. These results are important because ATC has historically had very limited effective systemic treatment options. However, they also show that a meaningful response is not guaranteed, and some tumours may remain stable, fail to shrink or progress despite treatment.

An objective response does not automatically mean that the cancer has been cured. A partial response means that measurable tumour deposits have reduced by the required amount on imaging, while a complete radiological response means that measurable disease is no longer visible. Microscopic malignant cells may still remain, and resistance can develop later. Therefore, even a very strong response requires continued treatment, monitoring and multidisciplinary reassessment [9,10].

Can Treatment Create an Opportunity for Surgery?

For some carefully selected patients, tumour shrinkage can create a treatment opportunity that was not available at diagnosis. An ATC tumour initially described as unresectable may separate from important structures or reduce enough for an experienced surgical team to reconsider complete or near-complete resection. This possibility is especially relevant when disease is concentrated in the neck and the distant tumour burden is absent or controlled.

However, tumour shrinkage and operability are not the same thing. A smaller tumour may still involve the carotid artery, trachea, oesophagus, mediastinum or other critical structures. Surgery should therefore be reconsidered through repeat imaging and joint review by surgeons, medical oncologists and radiation oncologists rather than being decided only from the percentage reduction in tumour size [1,17].

How I Explain This Treatment to a Patient

When I explain dabrafenib and trametinib to a patient, I describe the combination as a major treatment opportunity, but not as a guaranteed answer. It may control the disease, relieve pressure symptoms, reduce tumour volume and create time for surgery or radiation planning. The final benefit depends on how strongly the tumour responds, how long that response lasts and how effectively the treatment is integrated with the rest of the care plan.

If you receive this treatment, you should know what the oncology team intends to achieve. The objective may be to control metastatic disease, shrink an unresectable neck tumour, prepare for surgery, reduce immediate symptoms or combine systemic treatment with radiation. You should also receive a clear plan for fever, heart monitoring, eye symptoms, laboratory tests, response scans and urgent warning signs.

The most useful question is therefore not only, “Will dabrafenib and trametinib work?” A better question is, “If my tumour responds, how will my doctors use that response to improve the complete treatment pathway?” This approach ensures that a valuable response is translated into the best possible combination of systemic treatment, surgery, radiation, airway protection and supportive care.

Why BRAF V600E Has Become So Important in Anaplastic Thyroid Cancer

BRAF V600E has become one of the most clinically important molecular findings in anaplastic thyroid cancer because it can directly guide treatment. In the past, doctors mainly selected treatment according to tumour stage, location, operability and the patient’s general condition. These factors are still essential, but molecular testing can now reveal whether the tumour carries a specific abnormality that can be targeted with medicine.

For a patient with rapidly progressing ATC, this distinction is important. A confirmed BRAF V600E mutation may allow the oncology team to consider dabrafenib and trametinib early in the treatment pathway rather than relying only on conventional chemotherapy, radiation or symptom-directed care [1,2].

What the BRAF Gene Normally Does

The BRAF gene provides instructions for making a protein that participates in the MAPK signalling pathway. This pathway helps normal cells respond to signals controlling growth, division and survival.

In a healthy cell, the pathway is activated only when it is needed. It can be compared with a switch that turns on briefly, sends a growth signal and then turns off again.

The BRAF protein passes the signal to MEK, which then communicates with other proteins further down the pathway. Under normal conditions, this process remains controlled. In cancer cells, however, mutations may disturb this control and allow growth signals to remain active [7,8].

What Happens When BRAF V600E Is Present

In BRAF V600E, a specific change occurs in the BRAF protein. This alteration keeps the growth pathway active even when the cell has not received a normal signal to divide.

The cancer cell may therefore continue receiving instructions to grow, survive and multiply. It is as though the growth switch has become stuck in the “on” position.

This continuous signalling can contribute to aggressive tumour behaviour. However, it also creates a weakness that doctors may be able to target. Dabrafenib blocks the abnormal BRAF signal, while trametinib blocks MEK further down the same pathway. Together, they attempt to reduce the tumour’s dependence on this continuously active growth system [3,4,9].

Why the Mutation Is More Than a Diagnostic Finding

A BRAF V600E result does not merely help describe the tumour. It may change the treatment decision immediately.

When I review an ATC report, I do not see BRAF V600E as an isolated laboratory term. I see it as information that may influence the choice of systemic therapy, the urgency of starting treatment and the possibility of reassessing surgery after tumour shrinkage.

For the patient, this means the molecular report can have direct practical value. It may help answer whether a targeted treatment is available, whether the tumour should be monitored for a rapid response and whether an earlier decision that the tumour is inoperable should later be reconsidered.

BRAF V600E Is Usually a Tumour Mutation

Patients often ask whether a BRAF V600E result means their children or relatives are also at risk. In most cases of ATC, BRAF V600E is a somatic mutation. This means it developed within the tumour cells and is not automatically present throughout the rest of the body.

It is therefore different from an inherited mutation passed from a parent to a child. A tumour BRAF V600E result does not by itself prove a hereditary cancer syndrome.

If there is an unusual family history of thyroid cancer or another suspected inherited condition, the treating team may still recommend genetic counselling. However, that decision is separate from routine tumour BRAF testing.

Why “BRAF-Positive” Is Not Precise Enough

The phrase “BRAF-positive” can be misleading because not every BRAF alteration is the same. Dabrafenib and trametinib have their strongest ATC evidence in tumours carrying the specific BRAF V600E mutation.

A report mentioning a different BRAF mutation, BRAF fusion or uncertain BRAF alteration should not automatically be interpreted in the same way. The exact molecular result must be reviewed before treatment is selected.

Patients should therefore ask whether the report specifically states BRAF p.V600E or an equivalent molecular description. If the result is unclear, the pathology or molecular laboratory may need to confirm it before treatment begins.

Why BRAF V600E Does Not Explain the Whole Tumour

Even when BRAF V600E is present, ATC usually contains other molecular changes. Alterations involving TP53, TERT promoter and additional genes may affect how aggressively the tumour behaves and how long it remains sensitive to targeted treatment [7,8,20].

This helps explain why two patients with the same BRAF V600E mutation may have different responses. One patient may experience rapid and major tumour shrinkage, while another may achieve only temporary control or limited benefit.

The presence of BRAF V600E therefore identifies an important treatment target, but it does not make every tumour biologically identical. The stage, extent of invasion, metastatic burden, additional mutations and overall condition of the patient remain important.

Why Rapid Testing Matters

ATC may progress over a short period, so BRAF testing should not be delayed until several treatments have failed. Testing should begin as soon as adequate tumour material is available and should occur alongside airway assessment, staging and surgical review [1,2].

If your tumour is BRAF V600E-positive, the result may open an important treatment pathway. If it is negative, that does not mean that no targeted options exist. Broader molecular testing may identify other alterations that can influence treatment.

The central point is that modern ATC care should not rely only on how the tumour looks under the microscope. The molecular profile can help doctors understand what is driving the cancer and whether that driver can be targeted.

How Common Is BRAF V600E in Anaplastic Thyroid Cancer and Who Should Be Tested?

BRAF V600E is one of the most frequently detected actionable mutations in anaplastic thyroid cancer. Published studies report different rates because patient populations, tumour samples and testing methods are not identical. The American Thyroid Association guideline estimates that BRAF V600E may be present in approximately 40–70% of ATC tumours, although the frequency can be lower in some genomic series [1,7,8].

This variation does not reduce the importance of testing. Even if the mutation is found in only part of the ATC population, identifying it can immediately create a specific treatment option with dabrafenib and trametinib. For this reason, BRAF V600E testing should be treated as an urgent part of the initial ATC assessment rather than an optional test performed later.

Should Every Patient With ATC Be Tested?

Every patient with confirmed or strongly suspected anaplastic thyroid cancer should undergo rapid BRAF V600E testing whenever adequate tumour material is available [1,6]. Testing should not be limited to younger patients, metastatic disease or tumours already declared inoperable.

A patient with apparently resectable disease may also benefit from knowing the BRAF status. The result may become important if surgery leaves residual disease, the tumour progresses rapidly, distant metastases are identified or preoperative targeted treatment is being considered.

Similarly, an older patient or someone with advanced stage IVC disease should not automatically be excluded from molecular testing. Age alone does not determine whether targeted therapy can be considered. The decision also depends on the patient’s general condition, organ function, ability to take oral treatment, goals of care and expected balance between benefit and toxicity.

Why Testing Should Not Wait Until Other Treatments Fail

ATC can change quickly. During a delay of several weeks, a neck tumour may further compress the airway, affect swallowing or invade structures that were previously less involved.

For this reason, molecular testing should proceed at the same time as pathology confirmation, imaging, airway assessment and surgical review. Doctors should not wait for chemotherapy or radiation to fail before requesting the BRAF result [1,6].

When I assess a patient with ATC, I would want the molecular process to start immediately. A rapid BRAF result may help the oncology team make an early treatment decision, while broader genomic testing continues in parallel.

What Is Reflex BRAF Testing?

Reflex testing means that the pathology or molecular laboratory automatically begins BRAF V600E testing when ATC is diagnosed, without waiting for a later separate request. This approach can save important time in a rapidly progressive cancer.

Rapid testing may initially be performed with BRAF V600E immunohistochemistry or a focused molecular test. Broader DNA- and RNA-based next-generation sequencing can then provide a more complete view of the tumour [1,6].

The rapid test answers an immediate question: is BRAF V600E present? The broader panel answers a different question: are there additional mutations, fusions or biological features that could influence treatment now or after progression?

Why Some ATC Tumours Carry BRAF V600E

Some anaplastic thyroid cancers appear to develop through dedifferentiation of an earlier papillary thyroid cancer. This means that a previously more differentiated thyroid tumour gradually acquires additional molecular abnormalities and develops the aggressive features of ATC.

BRAF V600E may already be present in the papillary component and remain present after anaplastic transformation. Additional abnormalities involving genes such as TP53, TERT promoter and the PI3K–AKT pathway may then contribute to more aggressive behaviour [7,8].

This history helps explain why a pathology specimen may occasionally contain both differentiated thyroid cancer and anaplastic areas. It also explains why BRAF V600E alone does not describe the complete biology of the tumour.

What If the BRAF V600E Test Is Negative?

A negative BRAF V600E result does not mean that molecular testing has no further value. It means only that the specific mutation required for standard dabrafenib and trametinib treatment has not been identified in that specimen.

The oncology team should then consider broader molecular profiling. Some BRAF-negative ATC tumours may carry other potentially actionable alterations, including gene fusions or mutations involving different growth pathways [1,6,8].

The patient should not assume that “BRAF-negative” means “no treatment available.” Surgery, radiation, immunotherapy, chemotherapy, other mutation-directed treatments and clinical trials may still be considered according to the tumour profile and clinical condition.

What If the Sample Is Too Small or the Result Is Unclear?

ATC diagnosis is sometimes based on a small core biopsy or fine-needle aspiration sample. The available tissue may be sufficient to confirm cancer but insufficient for complete molecular testing.

If your report states that the sample was inadequate, indeterminate or failed quality control, that is not the same as a confirmed negative result. The treating team may request another tissue block, repeat the biopsy, test a metastatic site or consider circulating tumour DNA in selected circumstances.

An old BRAF-positive result from a previous papillary thyroid cancer may provide useful information, but the current anaplastic tumour should still be assessed whenever safely possible. Tumours can change over time, and the present disease may contain additional alterations that influence treatment.

The Practical Meaning for the Patient

You should know whether BRAF V600E testing has been ordered, which method was used and whether the result is confirmed. You should also ask whether broader DNA- and RNA-based profiling is being performed.

The most important principle is speed without sacrificing accuracy. Rapid BRAF testing may identify an immediate treatment option, while comprehensive profiling helps prepare for the wider treatment journey. In ATC, molecular testing is not simply a research exercise. It can influence what the medical team does next.

How Is BRAF V600E Testing Performed?

BRAF V600E testing examines tumour material to determine whether this specific mutation is present. The test is usually performed on tissue obtained during a core biopsy, surgery or another diagnostic procedure. In selected situations, tumour DNA circulating in the blood may also be examined, but blood-based testing does not yet replace good-quality tumour testing in every patient with anaplastic thyroid cancer [1,6,23].

The most suitable method depends on how urgently the result is needed, how much tissue is available and whether the oncology team also needs broader information about other mutations. In rapidly progressing ATC, doctors may use a fast BRAF-specific test first and arrange comprehensive molecular profiling at the same time.

BRAF V600E Immunohistochemistry

Immunohistochemistry uses a special antibody to detect the abnormal BRAF V600E protein within tumour cells. The pathologist applies the antibody to a prepared tissue section and examines whether the tumour shows the expected staining pattern.

This method can be useful because it is relatively fast and can often be performed in a hospital pathology laboratory. In an urgent ATC case, it may provide an early indication that the tumour is BRAF V600E-positive while a molecular test is still being completed [1,6].

Immunohistochemistry is not simply a blood test, and it does not look directly at the DNA sequence. It detects the protein produced by the mutated gene. The accuracy can therefore depend on tissue quality, fixation, staining technique and the pathologist’s interpretation.

A clear positive result may allow the multidisciplinary team to begin planning targeted treatment promptly. However, molecular confirmation may still be advisable, particularly when the staining is weak, uneven or inconsistent with the clinical and pathological findings.

PCR-Based Mutation Testing

Polymerase chain reaction, commonly called PCR, examines selected parts of the tumour DNA. A BRAF-specific PCR test is designed to determine whether the V600E alteration is present.

Because the test looks for a known mutation, it can provide a rapid and sensitive result even when the amount of tumour tissue is limited. This makes it useful when the immediate question is whether the patient qualifies for BRAF-directed treatment.

PCR is more focused than broad sequencing. It can confirm BRAF V600E, but it may not identify unrelated mutations or gene fusions elsewhere in the tumour. For this reason, PCR can answer the urgent treatment question without replacing comprehensive profiling.

The United States Food and Drug Administration has approved a companion diagnostic based on next-generation sequencing for identifying BRAF V600E-positive ATC patients who may be considered for dabrafenib and trametinib [5]. The exact platform used may differ between hospitals and countries, but the result should clearly state whether BRAF V600E was detected.

Next-Generation Sequencing

Next-generation sequencing, or NGS, examines many genes at the same time. Instead of searching only for BRAF V600E, it can identify a wider range of mutations, insertions, deletions and, depending on the panel, gene fusions.

This broader information is important because ATC is molecularly complex. A tumour may contain BRAF V600E together with additional alterations that affect aggressiveness, response duration or resistance. A BRAF-negative tumour may also carry another actionable alteration that changes the treatment pathway [6–8].

Some panels examine only DNA. Others examine both DNA and RNA. RNA testing can be particularly helpful for detecting gene fusions, which may be missed by a DNA-only panel in some cases.

When I review molecular testing for an ATC patient, I would prefer the immediate BRAF question and the wider genomic question to be addressed in parallel whenever possible. The rapid result may guide current treatment, while comprehensive sequencing may help if the tumour does not respond, later becomes resistant or requires another treatment strategy.

Testing Tissue From the Primary Tumour or a Metastasis

BRAF testing can often be performed on tissue from the thyroid or neck mass. If this sample is inadequate, tissue from a lymph node, lung metastasis or another accessible tumour site may sometimes be used.

The pathologist must confirm that the specimen contains enough viable tumour cells. A sample with extensive necrosis, blood, inflammation or very few malignant cells may not provide a reliable result.

This is particularly relevant in ATC because some tumours contain large areas of dead tissue. The biopsy may reach the mass but still fail to collect enough living cancer cells for molecular analysis.

If the laboratory reports insufficient tumour content, the result should not be treated as BRAF-negative. It means the test could not answer the question reliably.

Can an Old Thyroid Cancer Sample Be Used?

Some patients previously had papillary thyroid cancer and later developed ATC. In such cases, an older tissue block may already show BRAF V600E.

That result can be clinically useful, especially when obtaining new tissue is difficult. However, the current ATC tumour should still be tested whenever it can be done safely. The anaplastic tumour may have acquired additional mutations during its transformation, and those changes may influence treatment behaviour [7,8].

An old positive BRAF V600E result may support the presence of the target, but broader testing of the present disease can provide more complete information.

Liquid Biopsy and Circulating Tumour DNA

A liquid biopsy examines fragments of tumour DNA released into the bloodstream. It usually requires a blood sample rather than a surgical tissue sample.

This approach may be considered when tissue is insufficient, the tumour is difficult to biopsy or the patient’s condition makes another invasive procedure unsafe. It may also help detect new resistance mutations after treatment has started [19,23].

However, a negative blood result does not always prove that the tumour is BRAF-negative. Some tumours release only small amounts of DNA into the circulation, and the test may fail to detect a mutation that is present in the tissue.

For this reason, a positive circulating-DNA result may be clinically informative, but a negative result should be interpreted cautiously. Tumour-tissue testing remains preferable when adequate tissue can be obtained safely.

What If Two Tests Give Different Results?

Occasionally, immunohistochemistry may appear positive while molecular testing is negative, or one specimen may be positive while another is inconclusive. Such discordance does not always mean that one laboratory made a mistake.

Possible explanations include poor tissue quality, low tumour-cell content, technical differences between assays, tumour heterogeneity or sampling of different components of a mixed thyroid cancer.

The pathology and molecular teams should review the tissue, testing method and quality-control information together. Repeat testing with another method or another specimen may be necessary before a treatment decision is made.

A patient should not be started on dabrafenib and trametinib merely because a report uses a vague phrase such as “possible BRAF alteration.” The treatment decision should be based on a clearly documented BRAF V600E result or another sufficiently reliable clinical confirmation.

How Quickly Should the Result Be Available?

The exact turnaround time varies between hospitals and laboratories. A focused immunohistochemistry or PCR test may be available sooner than a broad NGS panel.

In ATC, the medical team should not wait passively for comprehensive sequencing when a rapid BRAF-specific test can be performed. At the same time, emergency airway treatment, imaging, nutritional support and assessment of operability should continue.

The testing process should therefore have two aims: obtaining the immediate BRAF V600E answer as quickly as possible and obtaining a broader molecular profile without unnecessary delay.

What the Patient Should Check on the Report

You should ask whether the report specifically states that BRAF V600E was detected, not detected or could not be assessed. These three conclusions have different meanings.

A negative result means the laboratory successfully tested adequate material and did not identify the mutation. An inadequate or failed result means that the mutation status remains unknown.

You should also ask which specimen was tested, which method was used and whether broader DNA- and RNA-based sequencing has been arranged. These details can prevent an inconclusive result from being mistaken for a confirmed negative finding.

In BRAF V600E-positive ATC, the molecular report can rapidly influence treatment. Accuracy matters, but so does speed. The best approach is not to choose between rapid testing and comprehensive testing. It is to use both appropriately so that the patient’s immediate and future treatment decisions are supported by reliable molecular information.

What Exactly Are Dabrafenib and Trametinib?

Dabrafenib and trametinib are oral targeted anticancer medicines used together for anaplastic thyroid cancer carrying the BRAF V600E mutation. They are not general medicines for every thyroid cancer, and they should not be started only because a tumour appears aggressive. Their role depends on confirming the specific molecular change that allows these medicines to target an important cancer-growth pathway [3,4].

Although both medicines act on the same pathway, they block it at different points. This combined action helps suppress the growth signal more effectively than blocking only one part of the pathway.

Dabrafenib Blocks the Abnormal BRAF Signal

Dabrafenib is known as a BRAF inhibitor. In a BRAF V600E-positive tumour, the altered BRAF protein remains continuously active and sends repeated signals that encourage cancer cells to grow and survive.

Dabrafenib attaches to the abnormal BRAF protein and reduces its activity. When the medicine successfully blocks this signal, tumour cells may slow their growth, stop dividing or begin to die.

The response is not identical in every patient. One tumour may shrink rapidly, another may remain stable, and another may show little benefit. This difference occurs because ATC may contain additional mutations and alternative survival pathways besides BRAF V600E.

Trametinib Blocks MEK Further Down the Pathway

Trametinib is a MEK inhibitor. MEK is situated below BRAF in the same MAPK growth pathway.

The pathway can be understood simply as:

BRAF V600E → MEK → ERK → tumour-cell growth

Dabrafenib blocks the abnormal BRAF signal near the beginning of the pathway. Trametinib blocks MEK further down. This dual blockade aims to reduce the chance that the growth signal will continue through the pathway despite BRAF inhibition [3,4,9].

Why Two Medicines Are Needed

If only BRAF is blocked, cancer cells may reactivate the pathway or use nearby signals to continue growing. Adding trametinib provides a second level of control.

I explain this to patients as closing two connected gates rather than only one. Dabrafenib closes the first gate at BRAF, and trametinib closes the next gate at MEK. This does not guarantee that every cancer cell will be controlled, but it makes pathway suppression more complete.

The combination is also used because clinical evidence in BRAF V600E-positive ATC has been developed with both medicines together. Dabrafenib alone is not the standard evidence-based regimen for this setting [9,10].

Are Dabrafenib and Trametinib Chemotherapy?

Dabrafenib and trametinib are not traditional chemotherapy. Conventional chemotherapy generally affects rapidly dividing cells throughout the body, including some healthy cells. Targeted therapy is designed to interfere with a particular molecular abnormality or signalling pathway that supports tumour growth.

This difference does not mean targeted therapy is mild or free from serious risks. Dabrafenib and trametinib can cause fever, dehydration, heart problems, eye complications, bleeding, skin reactions and other adverse effects. They require regular monitoring and should be prescribed by an oncology team experienced in managing targeted medicines [3,4].

Are These Medicines Immunotherapy?

Dabrafenib and trametinib are also different from immunotherapy. Immunotherapy attempts to help the immune system recognise and attack cancer cells. Dabrafenib and trametinib act directly on the BRAF–MEK growth pathway inside tumour cells.

Pembrolizumab is an example of immunotherapy that may be considered in selected ATC cases. It should not be confused with dabrafenib or trametinib, and adding it to the combination is not automatically necessary for every patient.

Why Oral Treatment Still Requires Close Supervision

Because these medicines are taken by mouth, some patients assume that they are simpler than intravenous cancer treatment. However, oral administration does not make them less powerful.

You must take the medicines according to the prescribed schedule, follow the fasting instructions and report side effects promptly. The oncology team may temporarily interrupt treatment, reduce a dose or restart it after symptoms improve. These changes are often made to protect the patient and do not necessarily mean that the treatment has failed.

What These Medicines Can and Cannot Do

Dabrafenib and trametinib may reduce tumour size, slow disease progression, relieve pressure-related symptoms and create an opportunity for surgery or radiation in selected patients. They may also control distant metastatic disease when the tumour remains sensitive to BRAF and MEK inhibition [9,10].

However, the medicines cannot guarantee complete tumour removal or permanent control. Some cancer cells may be resistant from the beginning, while others may develop resistance later.

For this reason, the best use of dabrafenib and trametinib is not as an isolated treatment. Their benefit should be repeatedly assessed alongside airway safety, imaging, surgical resectability, radiation planning, nutrition and the patient’s overall condition.

Why Are Dabrafenib and Trametinib Used Together Instead of Dabrafenib Alone?

Dabrafenib and trametinib are used together because BRAF V600E-positive anaplastic thyroid cancer depends on a signalling pathway that can remain active even when only one part of it is blocked. Dabrafenib inhibits the abnormal BRAF protein, while trametinib blocks MEK further downstream. By targeting both points, doctors can suppress the MAPK pathway more completely than with BRAF inhibition alone [3,4,9,10].

The clinical evidence that established targeted treatment for BRAF V600E-positive ATC is based on the combination of dabrafenib and trametinib. For this reason, the standard evidence-based approach is dual BRAF and MEK inhibition rather than dabrafenib monotherapy [9,10].

Why Blocking BRAF Alone May Not Be Enough

Cancer cells are biologically adaptable. Even when BRAF V600E is an important driver, the tumour may find ways to reactivate downstream signalling after BRAF is blocked.

If BRAF inhibition reduces the signal at the beginning of the pathway but MEK and ERK activity eventually becomes restored, cancer cells may begin growing again. This is one reason resistance can develop during targeted treatment.

The pathway can be viewed simply as:

BRAF V600E → MEK → ERK → tumour growth

Dabrafenib acts at BRAF. Trametinib acts at MEK. Using both medicines therefore suppresses the same cancer-growth pathway at two connected levels [3,4].

How Trametinib Strengthens BRAF-Directed Treatment

Trametinib does not replace dabrafenib. It supports BRAF-directed treatment by reducing signalling through MEK.

When both medicines work effectively, the tumour receives less growth signalling through the MAPK pathway. This may result in reduced cell proliferation, increased cancer-cell death and measurable tumour shrinkage.

I explain this to patients as shutting down a main road at two different points. If only one roadblock is placed, cancer cells may sometimes find a way around it. A second blockade further along the same pathway makes continued signalling more difficult.

This explanation is deliberately simple because the actual biology is more complicated. ATC cells can also activate completely different pathways, which is why even combined BRAF and MEK inhibition does not permanently control every tumour.

Does Combination Treatment Completely Prevent Resistance?

No. Trametinib can improve pathway suppression, but it cannot eliminate every possible mechanism of resistance.

Some tumours may be resistant from the beginning. Others may respond for months and later start growing again. Additional mutations involving RAS, PI3K signalling, TP53 or other molecular pathways may influence how long the treatment remains effective [7,8,19,20].

This is why doctors continue imaging and clinical monitoring even after an excellent initial response. A tumour that has shrunk substantially can still develop resistant populations of cancer cells later.

For you as a patient, an early response should therefore be viewed as an important treatment achievement rather than a reason to stop surveillance.

Why the Combination Became the Established ATC Regimen

The pivotal prospective studies in BRAF V600E-mutated ATC evaluated dabrafenib together with trametinib. The original phase II study demonstrated substantial antitumour activity, and the updated ROAR analysis confirmed meaningful responses in this aggressive cancer [9,10].

The updated study reported an objective response in approximately 56% of patients. These findings helped establish combined BRAF and MEK inhibition as an important targeted strategy in BRAF V600E-positive ATC [10].

The key point is that these results cannot simply be transferred to dabrafenib alone. When we discuss the response rates reported in ATC, we are discussing patients who received the combination.

Can Dabrafenib Ever Be Used Alone?

Dabrafenib has activity against BRAF V600E, but dabrafenib alone is not the established standard regimen for BRAF V600E-positive ATC when trametinib can be given safely.

There may be unusual clinical situations in which one drug has to be interrupted because of toxicity, a procedure or another medical problem. Such decisions should be made by the treating oncology team rather than by the patient.

A patient should never stop trametinib and continue dabrafenib independently simply because one medicine appears to be causing side effects. The toxicity may require interruption of one medicine, both medicines, dose reduction or additional evaluation depending on the problem [3,4].

Does Using Two Targeted Medicines Mean Twice the Toxicity?

Not necessarily, but combination treatment does create its own pattern of side effects and requires careful monitoring.

Fever is particularly important with dabrafenib and trametinib. Other clinically important problems can include dehydration, reduced heart function, eye complications, bleeding, skin reactions and elevated blood glucose [3,4].

The purpose of combining the medicines is therefore not simply to give “more treatment.” It is to improve biological control of the tumour while maintaining an acceptable balance between benefit and toxicity.

Doctors may temporarily interrupt treatment or reduce doses when side effects become significant. These adjustments are part of standard targeted-therapy management and do not automatically mean that the tumour has become resistant.

Why Both Medicines Should Be Viewed as One Treatment Strategy

Patients sometimes focus on dabrafenib because BRAF V600E is the mutation named on their molecular report. However, trametinib is not an optional supporting medicine added without reason.

The treatment strategy is better understood as combined BRAF–MEK blockade. Dabrafenib targets the primary abnormal signal, while trametinib reduces downstream signalling that could otherwise remain active.

When I discuss this combination with a patient, I therefore describe dabrafenib and trametinib as two parts of one molecular treatment plan. The objective is not only to attack the BRAF mutation but to control the pathway that the mutation is driving.

This distinction becomes especially important when we later assess response, toxicity and resistance. If the tumour shrinks, the benefit reflects the combined strategy. If it progresses, the oncology team must consider whether the cancer has developed a mechanism that allows it to escape both levels of pathway inhibition.

Who Is a Candidate for Dabrafenib and Trametinib?

Dabrafenib and trametinib are considered for patients whose anaplastic thyroid cancer carries a confirmed BRAF V600E mutation. The mutation is the key requirement because these medicines are designed to block the abnormal BRAF–MEK signalling pathway that drives tumour growth in this molecular subgroup [2–4].

The treatment decision, however, should not depend on the mutation alone. Doctors must also consider whether the tumour is resectable, whether it has spread to distant organs, how rapidly it is progressing, whether the airway is threatened, whether the patient can swallow oral medicine and whether the expected benefit is reasonable in relation to the patient’s overall condition.

Confirmed BRAF V600E Mutation Is the Starting Point

The patient should have a clearly documented BRAF V600E-positive result before dabrafenib and trametinib are started. A vague report such as “BRAF alteration detected” is not enough unless the exact alteration is confirmed to be V600E or otherwise judged appropriate by a molecular oncology team.

The result may come from tumour tissue tested by immunohistochemistry, PCR or next-generation sequencing. In selected cases, circulating tumour DNA may also contribute useful information, but tumour tissue remains the preferred source when it is available and adequate.

If your report is BRAF-negative, dabrafenib and trametinib should not automatically be used. The oncology team should instead review broader molecular profiling because another targetable alteration may be present.

Patients With Locally Advanced ATC

Dabrafenib and trametinib may be especially important in patients with locally advanced disease that cannot be removed safely at diagnosis. A large neck tumour may surround or invade the trachea, oesophagus, carotid artery, recurrent laryngeal nerve or structures extending into the mediastinum.

In this situation, the treatment objective may be to shrink the tumour and gain better control of the disease. If the tumour responds sufficiently, the patient can later be reassessed for surgery or radiation.

The current FDA indication includes BRAF V600E-positive locally advanced ATC when satisfactory locoregional treatment options are not available [3,4]. This does not mean that surgery or radiation should be ignored. It means targeted therapy may become the most important immediate systemic option when local treatment alone is not adequate.

Patients With Metastatic Stage IVC Disease

Dabrafenib and trametinib may also be used when ATC has spread beyond the neck to organs such as the lungs, bones or brain.

In metastatic disease, the treatment objective is usually broader systemic control rather than only shrinking the neck tumour. A successful response may reduce disease burden in several organs at the same time.

Even in stage IVC disease, local treatment may still be necessary. A neck tumour threatening the airway may need urgent intervention, and a painful bone metastasis or brain lesion may require radiation despite good systemic control elsewhere.

For this reason, metastatic disease does not mean that every treatment decision becomes purely systemic. Targeted therapy and local treatment often need to work together.

Patients With Borderline-Resectable or Initially Unresectable Disease

One of the most important groups to consider is the patient whose tumour is considered too extensive for meaningful surgery at diagnosis but may become operable if it shrinks.

In such cases, dabrafenib and trametinib may be used as induction or neoadjuvant therapy. The purpose is not simply to reduce tumour size on a scan. The real objective is to improve the relationship between the tumour and critical structures so that complete or near-complete resection may become possible.

When I review such a patient, I would want the surgical team involved from the beginning. A tumour should not be labelled permanently inoperable without reassessment if it responds strongly to BRAF-directed treatment.

What About Patients Whose Tumour Is Already Resectable?

A patient with an immediately resectable tumour should not automatically receive targeted therapy first simply because BRAF V600E is present.

If an experienced ATC surgeon believes the tumour can be completely or nearly completely removed without unacceptable morbidity, surgery may remain an important part of the initial treatment plan [1,2].

The role of dabrafenib and trametinib in this situation depends on the full clinical picture. The team may consider postoperative targeted treatment, preoperative treatment in selected cases or another multimodal sequence.

The important point is that BRAF positivity should not cause doctors to abandon a potentially valuable surgical opportunity.

Does Age Decide Eligibility?

Age alone does not determine whether a patient can receive dabrafenib and trametinib.

Many patients with ATC are older adults, and some may still tolerate targeted therapy well. Others may have significant heart disease, poor kidney function, severe frailty or other medical problems that increase treatment risk.

The oncology team therefore assesses physiological fitness rather than simply looking at the patient’s age. A fit 75-year-old may be a better treatment candidate than a much younger person with severe organ dysfunction.

For you as a patient, the important questions are how well your heart, kidneys and liver are functioning, whether you can maintain hydration and nutrition, and whether the treatment can be monitored safely.

Patients With Severe Swallowing Difficulty

ATC frequently affects swallowing because the tumour may compress the oesophagus, impair vocal-cord movement or cause aspiration.

This creates a practical problem because dabrafenib and trametinib are oral medicines. A patient who cannot safely swallow tablets or oral formulations requires early pharmacy, nutrition and swallowing-team involvement.

The medical team should determine whether an appropriate formulation can be administered safely and whether temporary enteral feeding is needed. Patients should not crush, open or manipulate medicines independently unless the oncology pharmacist has specifically advised how the prescribed formulation should be given.

Patients With Airway Compromise

A BRAF V600E-positive result does not make dabrafenib and trametinib a substitute for emergency airway management.

If a patient has stridor, rapidly worsening breathlessness, severe tracheal narrowing or inability to lie flat, airway protection must be assessed immediately. Targeted therapy may work quickly in some patients, but doctors should never assume that tumour shrinkage will occur soon enough to prevent an airway emergency [1].

This is one of the most important practical principles in ATC care. Molecular treatment and emergency airway planning must proceed together.

Patients With Heart Disease

Trametinib can reduce left ventricular ejection fraction and may cause cardiomyopathy in some patients [4]. A history of heart failure, reduced cardiac function or significant cardiovascular disease therefore requires careful assessment before treatment begins.

This does not automatically exclude the patient. The oncology team may request an echocardiogram or another cardiac assessment before treatment and continue monitoring during therapy.

If heart function deteriorates, treatment may need to be interrupted, modified or stopped depending on severity.

Patients With Eye Disease

Trametinib can cause retinal and other ocular complications. Patients with a history of retinal disease, visual disturbance or other significant eye problems should inform the oncology team before treatment starts [4].

New blurred vision, flashes, floaters, visual-field loss or sudden deterioration in sight during treatment should be assessed urgently.

Eye disease does not necessarily prevent therapy, but it can affect how closely the patient needs to be monitored.

Patients With Diabetes or High Blood Sugar

Dabrafenib and trametinib can contribute to hyperglycaemia in some patients [3,4]. A person with diabetes may therefore require closer glucose monitoring and adjustments to diabetic treatment.

The oncology team should know whether the patient is taking insulin, metformin or other glucose-lowering medicines before targeted therapy begins.

Poorly controlled diabetes may also become more difficult during febrile episodes, dehydration or reduced oral intake.

Patients With Active Infection or Recurrent Fever

Fever is a common and important toxicity of dabrafenib and trametinib. At the same time, patients with ATC may develop pneumonia, aspiration, urinary infection or other infections.

If a patient already has fever before treatment starts, the cause should be assessed. Starting targeted therapy in the presence of an untreated infection can make later interpretation difficult because treatment-related pyrexia and infection may appear similar.

A clear baseline assessment helps the team distinguish these problems more safely.

Patients Taking Many Medicines or Supplements

Dabrafenib has clinically important drug-interaction potential. Patients should therefore provide a complete list of prescription medicines, over-the-counter drugs, nutritional supplements, herbal products and Ayurvedic formulations before treatment begins [3].

I would not advise a patient to assume that a natural product is automatically safe with targeted therapy. Some products may affect liver enzymes, blood glucose, bleeding risk or drug metabolism.

The oncology pharmacist should review the full medication list and identify possible interactions before treatment starts.

Performance Status and Treatment Goals Matter

A patient’s functional condition is an important part of the decision. Someone who is walking, eating, communicating and managing daily activities may tolerate treatment differently from a patient who is severely debilitated, bedbound or experiencing major organ failure.

The treatment objective should also be clear. In one patient, the goal may be to shrink the tumour enough for surgery. In another, it may be to control metastatic disease. In a third, it may be to reduce neck symptoms and preserve breathing or swallowing.

The same medicines can therefore be used with different clinical objectives.

The Best Candidate Is Defined by More Than One Test Result

A BRAF V600E-positive result opens the door to dabrafenib and trametinib, but it does not complete the treatment decision.

The best candidate is someone in whom the mutation has been reliably confirmed, the expected benefit is meaningful, the treatment can be administered safely and the oncology team has a clear plan for monitoring, imaging and reassessment.

If you are BRAF V600E-positive, the next question should not simply be, “Can I take these medicines?” It should be, “What are we trying to achieve with them, and how will we use the response if the tumour shrinks?”

That question turns targeted therapy from a prescription into a complete treatment strategy.

What Should Happen in the First 24–72 Hours After BRAF V600E–Positive ATC Is Diagnosed?

The first 24–72 hours after an anaplastic thyroid cancer diagnosis can be critical because the tumour may progress quickly and threaten breathing, swallowing or major structures in the neck. Once BRAF V600E is confirmed, the treatment team should move rapidly, but speed should not replace careful coordination. Airway safety, staging, resectability and treatment planning should all proceed together [1,2].

Airway Assessment Comes First

If the patient has stridor, rapidly worsening breathlessness, difficulty lying flat or severe tracheal compression, airway assessment becomes the immediate priority. Dabrafenib and trametinib can produce rapid responses in some patients, but doctors cannot rely on future tumour shrinkage when the airway is already unstable [1].

I would always want the airway plan defined before assuming that targeted therapy alone will solve an urgent obstruction.

Swallowing and Aspiration Must Be Checked Early

ATC can interfere with swallowing through oesophageal compression, recurrent laryngeal nerve involvement or impaired vocal-cord movement. Coughing during meals, choking, a wet voice or recurrent chest infection may suggest aspiration.

If you cannot swallow safely, the team should involve swallowing and nutrition specialists early. Maintaining hydration and nutrition becomes especially important because dabrafenib and trametinib are oral treatments.

Diagnosis and BRAF Status Should Be Confirmed Quickly

The pathology should confirm that the tumour is truly anaplastic thyroid carcinoma. At the same time, the BRAF V600E result should be verified using an appropriate molecular or pathological method.

Broader molecular profiling should also be initiated because additional alterations may become important later, particularly if BRAF-directed therapy does not work or eventually loses effectiveness [1,6].

Staging Should Not Be Delayed

Imaging should define the extent of disease in the neck and identify distant metastases. Doctors need to know whether the tumour involves the trachea, oesophagus, carotid arteries or mediastinum and whether disease has spread to organs such as the lungs, bones or brain.

This information influences whether the main objective is systemic control, conversion to surgery, local symptom control or a combination of these goals.

Resectability Should Be Assessed Before and After Targeted Therapy

A surgeon experienced in ATC should review whether complete or near-complete removal is technically possible. Some tumours are clearly unresectable at diagnosis, while others are borderline and may become more favourable after targeted therapy.

Importantly, a decision that the tumour is inoperable at diagnosis should not always be viewed as permanent. If the tumour responds substantially to dabrafenib and trametinib, resectability should be reassessed.

The Multidisciplinary Team Should Decide the Sequence

ATC management rarely depends on one specialist. The ideal discussion includes medical oncology, thyroid or head-and-neck surgery, radiation oncology, pathology, radiology and appropriate airway, swallowing and nutrition specialists [1,2].

When I discuss treatment with a patient, I would want one clear question answered at this stage: What are we trying to achieve first? The answer may be airway protection, rapid tumour shrinkage, preparation for surgery, control of metastatic disease or stabilisation before radiation.

Once that objective is clear, dabrafenib and trametinib can be positioned properly within the wider treatment plan rather than being used as an isolated treatment decision.

Stage IVA, IVB and IVC — Does Stage Decide Whether Dabrafenib and Trametinib Are Used?

Stage is important in anaplastic thyroid cancer, but it does not by itself decide whether dabrafenib and trametinib should be used. The more useful clinical questions are whether the tumour carries BRAF V600E, whether it is resectable, whether distant metastases are present and what the immediate treatment goal is [1,2].

Two patients with the same stage may therefore receive different treatment sequences.

Stage IVA Disease

Stage IVA generally represents disease that remains confined to the thyroid region without the more extensive local invasion seen in advanced stage IVB disease. If the tumour can be completely or nearly completely removed, surgery may remain an important early treatment option.

A BRAF V600E-positive result is still valuable because targeted therapy may later be considered if residual disease remains, the tumour progresses or a multidisciplinary team believes preoperative treatment could improve resectability.

The presence of BRAF V600E should therefore not automatically replace surgery when meaningful complete resection is already possible.

Stage IVB Disease

Stage IVB disease involves more extensive growth beyond the thyroid into important structures of the neck or upper chest. These tumours may involve the trachea, oesophagus, major blood vessels, nerves or mediastinal structures.

This is where dabrafenib and trametinib can become particularly important in BRAF V600E-positive disease. If the tumour is initially unresectable or surgery would cause unacceptable morbidity, targeted therapy may be used to reduce tumour burden and control disease [1,2].

If a substantial response occurs, the surgical team should reassess the patient. A tumour described as unresectable before treatment may have a different relationship with surrounding structures after several weeks of effective therapy.

Stage IVC Disease

Stage IVC means that the cancer has spread to distant organs. Common sites can include the lungs, bones and, less commonly, the brain or other organs.

In this setting, dabrafenib and trametinib primarily function as systemic treatment. The objective is to control disease throughout the body rather than focusing only on the thyroid mass.

Local treatment may still remain important. A neck tumour threatening the airway may require urgent local management, while painful bone metastases, brain lesions or other symptomatic sites may require radiation or another directed intervention.

Why Resectability Can Matter More Than the Stage Label

Stage describes how far the cancer has spread, but resectability describes whether meaningful surgery can actually be performed. These are related but different concepts.

A stage IVB tumour may initially be unresectable but later become operable after targeted therapy. Conversely, a patient with less extensive disease may still be a poor surgical candidate because of anatomy, severe comorbidities or unacceptable operative risk.

When I discuss treatment with a patient, I therefore do not ask only, “What stage is the cancer?” I also ask, “Can it be removed now, could it become removable after treatment, and is there distant disease that changes the overall strategy?”

For a BRAF V600E-positive patient, the most appropriate plan usually comes from combining stage, resectability, molecular status and treatment goals rather than allowing any one of these factors to determine treatment alone.

How Are Dabrafenib and Trametinib Taken?

Dabrafenib and trametinib are oral targeted medicines, but they need to be taken on a consistent schedule. For adults with BRAF V600E-positive anaplastic thyroid cancer, the standard regimen is dabrafenib 150 mg twice daily together with trametinib 2 mg once daily [3,4]. The current prescribing information continues to support this dosing approach. (DailyMed)

Treatment is generally continued while the cancer remains controlled and the side effects remain manageable. Temporary interruption or dose reduction may sometimes be necessary because of fever or another toxicity, but patients should not change the dose themselves.

How Should the Medicines Be Timed?

Dabrafenib is usually taken approximately 12 hours apart. Trametinib is taken once daily and can be taken with either the morning or evening dabrafenib dose.

Both medicines should generally be taken on an empty stomach, at least one hour before or two hours after food [3,4]. This matters because food can alter how the medicines are absorbed.

Patients should try to take their doses at approximately the same times every day. A consistent routine also makes missed doses less likely.

What Happens If a Dose Is Missed?

The missed-dose instructions are different for the two medicines. If a dabrafenib dose is missed and the next scheduled dose is less than six hours away, the missed dose should be skipped. For trametinib, a missed dose should generally be skipped when the next dose is less than 12 hours away [3,4].

The patient should not take a double dose to compensate. If vomiting occurs after taking either medicine, another dose should not be taken immediately; the next dose is taken at the usual scheduled time.

What If the Patient Cannot Swallow Normally?

Swallowing can become difficult in ATC because the tumour may compress the oesophagus or affect normal throat function. This issue should be identified before treatment starts rather than waiting until the patient begins missing doses.

Alternative oral formulations are available in some settings, but the exact preparation and method of administration must be determined by the oncology pharmacist. Tablets or capsules should not be crushed, opened or altered without specific instructions because doing so may change drug delivery or expose caregivers unnecessarily. Current labels include non-capsule/tablet formulations for appropriate patients.

How Long Is Treatment Continued?

There is no fixed number of weeks or months that applies to every ATC patient. Treatment may continue while the tumour is responding or remaining controlled and toxicity remains acceptable [3,4].

If the tumour shrinks sufficiently for surgery, the treatment schedule may need to be interrupted around the operation. If significant toxicity develops, treatment may also be temporarily withheld and restarted at the same or a reduced dose according to the oncology team’s assessment.

For the patient, the important principle is consistency. Dabrafenib and trametinib should be treated as a carefully monitored cancer regimen, not simply as tablets taken at home.

How Effective Are Dabrafenib and Trametinib in BRAF V600E–Positive ATC?

Dabrafenib and trametinib have produced clinically meaningful tumour responses in a substantial proportion of patients with BRAF V600E–positive anaplastic thyroid cancer. This is important because ATC often progresses rapidly and historically had few effective systemic treatment options.

However, the treatment does not work equally well for every patient. Some tumours shrink significantly, some remain stable, and others continue to progress despite therapy. The available evidence supports genuine treatment benefit, but it should not be interpreted as a guarantee of response or cure [9–11].

What the Original Clinical Study Showed

The first prospective ATC results came from a phase II basket trial evaluating dabrafenib together with trametinib in patients with BRAF V600E-mutated cancers. The early ATC group was small, but it showed a high level of antitumour activity and established that combined BRAF and MEK inhibition could produce important responses in this aggressive disease [9].

These initial findings changed clinical practice because they demonstrated that a tumour previously treated mainly according to its anatomical extent could also be treated according to a specific molecular driver.

What the Updated ROAR Study Found

The updated ROAR analysis included 36 patients with BRAF V600E-mutated ATC. Approximately 56% achieved an objective response according to investigator assessment [10].

An objective response means that the measurable cancer reduced sufficiently on imaging to meet recognised response criteria. It includes both complete and partial responses.

The updated study reported three complete responses, while most responding patients achieved a partial response. Median progression-free survival was approximately 6.7 months, and median overall survival was about 14.5 months [10].

These are median figures, not fixed limits for an individual patient. Some patients progressed earlier, while others remained controlled considerably longer.

What the FDA Review Reported

The independent FDA assessment reported an objective response rate of 53% among 36 evaluable patients. This included a 6% complete response rate and a 47% partial response rate [3].

Among patients who responded, the median duration of response was 13.6 months. Approximately 68% of responses continued for at least six months [3].

The FDA result of 53% and the investigator-reported result of approximately 56% are not contradictory. They reflect different reviewers applying formal response criteria to the same general body of clinical evidence.

Why the Response Rate Is Important in ATC

A response rate of approximately half is clinically significant in a cancer that can worsen over a very short period. Tumour shrinkage may relieve pressure on the trachea or oesophagus, improve swallowing, reduce neck swelling and create time for further treatment planning.

In selected patients, a strong response may also change whether surgery is considered possible. The true value of treatment is therefore not limited to what appears on a scan. The response may alter the entire treatment pathway.

When I explain this evidence to a patient, I emphasise that a good response should be used actively. The team should ask whether the tumour has become more resectable, whether radiation should be added and whether distant disease is also controlled.

Why Individual Results Can Be Different

The clinical studies included relatively small numbers because ATC is rare. They were also nonrandomised, meaning that dabrafenib and trametinib were not directly compared with another treatment in a large controlled trial.

Patients enrolled in a study may also differ from those seen in emergency practice. Some real-world patients have severe airway compromise, poor nutrition, major organ dysfunction or very advanced disease that may affect outcomes [15,21].

ATC can also carry additional mutations besides BRAF V600E. These may influence how strongly the tumour responds and how long the benefit lasts.

You should therefore view the published response rate as a useful population estimate, not a prediction of your exact result. The most reliable assessment comes from monitoring symptoms, examination findings and repeat imaging after treatment begins.

What Does a 53–56% Response Rate Actually Mean for a Patient?

The reported 53–56% response rate means that approximately half of the patients in the main clinical evidence experienced enough tumour shrinkage to meet formal imaging criteria for an objective response [3,10]. It does not mean that every second patient was cured, and it does not predict exactly what will happen to one individual.

When you read a response percentage, it is important to understand what doctors counted as a response and what they did not.

What Is an Objective Response?

An objective response is a measurable reduction in tumour size confirmed on imaging. It includes both complete responses and partial responses.

In the FDA assessment, 53% of evaluable patients responded. About 6% achieved a complete response, while 47% achieved a partial response [3]. The updated ROAR analysis reported a similar overall response of approximately 56% [10].

These percentages describe what happened within the study population. They should be used to understand the likelihood of benefit, not as a promise of a particular outcome.

What Is a Partial Response?

A partial response means that the measurable tumour burden has reduced significantly, but cancer is still visible on imaging.

For an ATC patient, a partial response can still be extremely valuable. The tumour may place less pressure on the trachea, swallowing may improve, neck swelling may decrease, and surgery or radiation may become more practical.

A partial response should therefore not be viewed as an incomplete failure. In a rapidly progressing cancer, substantial shrinkage can change the entire treatment plan.

What Is a Complete Response?

A complete response means that measurable cancer is no longer visible on the scan. This is encouraging, but it is not automatically the same as cure.

Microscopic cancer cells may remain even when imaging appears clear. The patient still requires ongoing treatment, surveillance and multidisciplinary review because recurrence or resistance may occur later [9,10].

When I explain a complete response, I describe it as the best visible imaging result, not proof that every malignant cell has been permanently eliminated.

What Does Stable Disease Mean?

Stable disease means that the tumour has neither shrunk enough to qualify as a response nor grown enough to meet the definition of progression.

In many cancers, this can still represent benefit. In ATC, where untreated disease may enlarge rapidly, preventing further growth for a meaningful period can help preserve breathing, swallowing and general function.

The medical team must still decide whether stable disease is sufficient for the patient’s treatment goal. If the tumour continues threatening the airway or remains unresectable, stability alone may not be enough.

What Does Progressive Disease Mean?

Progressive disease means that the cancer has grown significantly or new tumour sites have appeared despite treatment.

This may occur because the tumour was resistant from the beginning or because resistance developed after an initial benefit. Progression should lead to a careful review of adherence, imaging, molecular findings and alternative treatment options.

Response Rate Is Not the Same as Survival Rate

A response rate measures tumour shrinkage. It does not tell us exactly how long a patient will live.

Some patients may have a strong response that lasts many months, while others may respond briefly. A patient with stable disease may sometimes remain controlled longer than another patient whose tumour initially shrinks but quickly becomes resistant.

For you as a patient, the most important issue is not only whether the tumour responds. It is whether the response lasts, improves symptoms, controls distant disease and creates a useful opportunity for surgery, radiation or continued systemic treatment [10,15].

How Quickly Can Dabrafenib and Trametinib Start Working?

Dabrafenib and trametinib can sometimes produce noticeable improvement within days or weeks, but there is no fixed response time for every patient. Some tumours begin shrinking relatively early, while others respond more slowly or do not respond sufficiently [9,10].

Because anaplastic thyroid cancer can progress rapidly, doctors should not wait only for a routine scan to judge whether treatment is helping. Breathing, swallowing, neck swelling, pain and general function should be reassessed from the beginning.

Why the Speed of Response Matters

A neck tumour may compress the trachea, oesophagus, voice nerves or major blood vessels. In this situation, even a modest early reduction can be clinically important.

The patient may notice that breathing becomes easier, pressure in the neck decreases or swallowing improves. These changes can suggest that the tumour is responding, but they do not replace imaging or formal medical assessment.

If your breathing is already unstable, the team must not depend on the possibility of a rapid drug response. Airway protection and emergency treatment should proceed whenever clinically necessary [1].

Which Early Changes May Suggest a Response?

Doctors may look for reduction in visible or palpable neck swelling, improved ability to lie flat, less breathlessness, reduced coughing, easier swallowing and improved voice or pain.

I would also ask whether the patient is eating better, sleeping more comfortably and needing less supportive treatment. These practical changes can be meaningful, especially when symptoms were worsening before targeted therapy began.

However, symptoms may also improve because of steroids, pain treatment, fluid drainage or other supportive measures. The response should therefore be confirmed objectively.

When Is Imaging Repeated?

The first scan is timed according to the urgency of the case and the treatment objective. A patient receiving therapy to make an unresectable tumour operable may need earlier imaging than someone with stable metastatic disease.

Published neoadjuvant experience shows that substantial tumour reduction can sometimes occur within a period that allows surgical reassessment [12,13]. The exact timing should be decided by the multidisciplinary team rather than applying one schedule to every patient.

Why Early Improvement Does Not Mean Treatment Can Stop

Even when the tumour appears to shrink quickly, treatment should not be stopped without oncology guidance. A visible improvement does not confirm that all tumour sites have responded or that microscopic disease has disappeared.

The team should assess the neck tumour, lymph nodes and distant metastases together. The most important question is not only how quickly the tumour responds, but whether that response is deep enough and durable enough to change the next treatment decision.

Dabrafenib and Trametinib Survival: How Should Patients Interpret the Numbers?

Survival statistics can help patients understand the overall evidence, but they cannot predict exactly how long one person will live. In the updated ROAR study, the median overall survival was approximately 14.5 months, while the median progression-free survival was about 6.7 months [10]. These figures describe the experience of the study group and should not be treated as a fixed limit for every patient.

What Does Median Overall Survival Mean?

Median overall survival is the point at which half of the study participants had died and half were still alive. It does not mean that every patient lives for exactly 14.5 months.

Some patients may experience rapid progression despite treatment, while others may achieve a durable response and live considerably longer than the median. Individual outcomes depend on the extent of disease, response to treatment, general health, additional tumour mutations and whether surgery or radiation becomes possible.

What Is Progression-Free Survival?

Progression-free survival measures how long patients remain alive without the cancer showing significant growth or new spread.

A median progression-free survival of 6.7 months does not mean that treatment automatically stops working at that point. Some patients progress earlier, while others remain controlled much longer. The duration of response may also differ from progression-free survival because these measurements describe different aspects of treatment benefit [10].

Why Modern ATC Survival May Differ From Older Statistics

Many older ATC survival figures were recorded before rapid molecular testing and BRAF-directed therapy became widely available. Modern treatment may include targeted therapy, specialised surgery, advanced radiation, immunotherapy and better airway and nutritional support.

Large observational studies have reported improving survival during more recent treatment periods, particularly when patients received mutation-directed and multimodal care [17,22]. However, these studies cannot prove that one treatment alone caused the improvement because patients selected for intensive treatment may also have been fitter or had more favourable disease.

Why Two BRAF V600E–Positive Patients May Have Different Outcomes

BRAF V600E does not act alone. Additional alterations, including TP53 and other molecular changes, may affect tumour aggressiveness and the duration of response [20].

When I discuss prognosis with a patient, I therefore avoid using one published number as a personal deadline. A more useful approach is to assess whether the tumour is responding, whether the response is sustained, whether symptoms are improving and whether the response creates an opportunity for surgery or stronger local control.

For you and your family, survival statistics should support informed planning without removing hope. The most meaningful prognosis becomes clearer only after the first weeks of treatment and the first formal response assessment.

Can Dabrafenib and Trametinib Make an Inoperable ATC Tumour Operable?

Yes, in selected patients with BRAF V600E-positive anaplastic thyroid cancer, dabrafenib and trametinib can shrink an initially unresectable tumour enough for surgery to be reconsidered. This is one of the most important developments in modern ATC treatment, although conversion to surgery is not guaranteed and the evidence mainly comes from specialised-centre observational studies rather than randomized trials [12,13].

The purpose of treatment in this situation is called neoadjuvant therapy. Instead of accepting the first assessment of inoperability as permanent, doctors use targeted treatment to reduce tumour burden and then reassess the relationship between the cancer and critical structures in the neck.

What Does “Unresectable” Actually Mean?

An ATC tumour may be considered unresectable when meaningful removal cannot be achieved without unacceptable damage to structures such as the carotid arteries, trachea, oesophagus, major nerves or deep tissues of the neck. Extensive mediastinal involvement or uncontrolled distant disease can also influence whether surgery would provide worthwhile benefit [1,13].

Importantly, unresectable does not necessarily mean that the tumour is physically impossible to touch. It means that an operation capable of achieving useful cancer clearance is not considered reasonable at that time.

How Targeted Therapy Can Change the Anatomy

When dabrafenib and trametinib work strongly, the tumour may contract away from structures that previously prevented surgery. For example, a tumour surrounding a major blood vessel may reduce sufficiently for the surgeon to identify a safer surgical plane. One published cohort specifically documented regression of tumour away from the common carotid artery after BRAF-directed therapy [13]. 

This is why tumour response should not be judged only by asking how many centimetres the mass has decreased. A smaller change in size can sometimes produce a major improvement in resectability if the tumour separates from a critical structure.

What Did the First Surgical Series Show?

A landmark 2019 report described six patients with initially unresectable BRAF V600E-mutated ATC who received neoadjuvant dabrafenib and trametinib and subsequently underwent complete surgical resection [12]. The experience demonstrated that targeted treatment could potentially change the role of surgery in carefully selected patients who would previously have been considered unsuitable for complete resection. 

This was an important proof of concept, but it involved only six patients at a highly specialised centre. We therefore should not tell every patient with unresectable BRAF V600E-positive ATC that treatment will make surgery possible.

What Did the Larger Experience Show?

A later retrospective cohort from the same specialist centre examined patients treated with BRAF-directed therapy and subsequently considered for surgery. The investigators reported encouraging outcomes among selected patients who responded sufficiently to proceed to resection [13]. They also suggested reassessing surgery when the tumour response begins to plateau rather than waiting indefinitely, because resistance and renewed tumour progression can eventually occur. 

However, these results must be interpreted carefully. Patients who responded well enough and remained healthy enough to undergo surgery were naturally different from patients with rapidly progressive disease who never reached an operation. Therefore, the studies show that the strategy can work in selected patients, but they do not prove that surgery itself caused all of the observed survival advantage.

Tumour Shrinkage Does Not Automatically Mean Operability

If your scan shows a major response, the next question should be whether the anatomy has changed sufficiently for meaningful surgery. The surgeon should reassess carotid involvement, tracheal and oesophageal invasion, mediastinal extension, vocal-cord function, distant metastases and the likelihood of achieving complete or near-complete resection [1,12,13]. 

When I explain this to a patient, I would not say, “The tumour has shrunk, therefore you can have surgery.” I would say, “The tumour has responded; now an experienced ATC surgical team should look again.”

That distinction is crucial. The real value of neoadjuvant dabrafenib and trametinib is not simply making the tumour smaller. It is the possibility that a successful response may create a new treatment opportunity that did not exist at diagnosis.

How Do Doctors Decide Whether Surgery Has Become Possible?

After a good response to dabrafenib and trametinib, the next step is not automatically surgery. The multidisciplinary team must reassess whether the tumour can now be removed with an acceptable level of risk and whether surgery is likely to provide meaningful disease control [1,12–14].

This decision depends much more on where the tumour is still attached or invading than on the percentage reduction in size alone.

Repeat Imaging Is Essential

Contrast-enhanced CT of the neck and chest is usually central to surgical reassessment. The team compares the new images with the scans taken before targeted therapy and looks carefully at the tumour’s relationship with critical structures.

If you have had a major response, the surgeon wants to know whether the tumour has pulled away from structures that previously made surgery unsafe or incomplete.

MRI or other imaging may occasionally be added when soft-tissue relationships are difficult to define.

Carotid Artery Involvement

The carotid arteries are among the most important structures assessed. A tumour that completely surrounds or extensively invades a carotid artery may make complete resection extremely difficult.

After effective targeted therapy, the tumour may shrink away from the artery or reduce the degree of encasement. This type of anatomical improvement can be more important for operability than simply measuring a smaller tumour diameter [12,13].

Tracheal and Oesophageal Involvement

Doctors also examine whether the tumour continues to invade the trachea or oesophagus.

Limited involvement may sometimes be managed surgically, whereas extensive invasion may require major reconstruction or make the operation unreasonably morbid. The expected effect on breathing, swallowing and quality of life must therefore be considered alongside cancer control.

Mediastinal and Deep Neck Extension

Tumour extending into the upper chest or deep prevertebral tissues can make surgery more complex. Repeat imaging helps determine whether targeted treatment has reduced this extension enough to create safer surgical planes.

The operation should not be pursued merely because some shrinkage has occurred. The surgeon must believe that useful gross tumour removal is technically achievable.

Distant Metastases Also Influence the Decision

A tumour may become technically resectable in the neck while distant disease continues to progress. In that situation, the team must consider whether major surgery will still provide enough benefit.

Conversely, if metastatic disease is well controlled and the neck tumour has become operable, surgery may become more attractive as part of a multimodal strategy.

Performance Status and General Fitness Matter

The patient must also be strong enough to tolerate surgery. Nutrition, cardiac function, respiratory status, swallowing ability and overall functional condition can influence the final decision.

When I review such a patient, I would want both questions answered: Can the tumour now be removed, and can the patient safely undergo the operation?

A major response to dabrafenib and trametinib therefore creates an opportunity for reassessment, not an automatic indication for surgery. The final decision should be based on anatomy, distant disease, expected surgical margins, functional consequences and the patient’s overall condition [1,12–14].

What Is the Difference Between R0, R1 and R2 Surgery?

When doctors discuss surgery for anaplastic thyroid cancer, they often use the terms R0, R1 and R2 resection. These terms describe how much tumour remains after surgery and help the medical team estimate the quality of local tumour removal [1,12,13].

This distinction becomes especially important when dabrafenib and trametinib have converted an initially unresectable tumour into one that may now be surgically manageable.

What Is an R0 Resection?

An R0 resection means that the surgeon has removed all visible tumour and the pathologist finds no cancer cells at the microscopic surgical margins.

In simple terms, there is no known tumour left at the edges of the removed specimen. This is generally the most desirable surgical result when it can be achieved safely.

However, an R0 resection does not guarantee that ATC has been cured. Microscopic cancer cells may exist elsewhere in the body, particularly when lymph-node or distant metastatic disease has already developed. Additional systemic treatment or radiation may therefore still be necessary [1].

What Is an R1 Resection?

An R1 resection means that the surgeon has removed all visible tumour, but microscopic examination shows cancer cells at or very close to a surgical margin.

Nothing obvious may remain in the neck after surgery, yet microscopic residual disease is still possible.

In ATC, an R1 resection may sometimes be accepted when trying to remove additional tissue would create major damage to the trachea, oesophagus, nerves or blood vessels. Postoperative radiation and systemic treatment may then be considered to strengthen local and overall disease control [1,13].

What Is an R2 Resection?

An R2 resection means that visible tumour remains after the operation. This usually occurs when the cancer cannot be safely separated from critical structures.

R2 surgery is therefore very different from R0 or R1 surgery. Removing part of a large tumour may occasionally help a specific symptom, but it should not be described as complete surgical removal.

This distinction is especially important for patients who have responded to targeted therapy. The aim of neoadjuvant dabrafenib and trametinib is not simply to make some surgery technically possible. The more meaningful objective is to create a realistic opportunity for complete gross removal, ideally an R0 or selected R1 resection [12,13].

Why Surgical Margin Status Matters After Targeted Therapy

When I discuss surgery after a strong treatment response, I would want to know what the surgeon realistically expects to achieve. If extensive visible disease is likely to remain, the benefit of a major operation may be very different from an operation expected to remove all gross tumour.

For you as a patient, it is reasonable to ask whether the planned operation is expected to achieve R0, R1 or R2 resection and what that result would mean for subsequent radiation and systemic treatment.

The key goal is not surgery for its own sake. It is to use surgery when it can contribute meaningfully to long-term local control as part of the complete ATC treatment strategy.

What Happens to Dabrafenib and Trametinib Around Surgery?

If dabrafenib and trametinib shrink an initially unresectable BRAF V600E-positive ATC enough for surgery, the medicines usually need to be coordinated carefully around the operation. The objective is to minimize surgical and wound-healing risks while avoiding an unnecessarily long interruption of systemic cancer control [12,13].

Published experience provides useful guidance, but there is no single perioperative schedule that should be applied automatically to every patient.

Why Treatment May Be Temporarily Interrupted

Trametinib is generally stopped several days before surgery because MEK inhibition may interfere with wound healing. Dabrafenib has a shorter pharmacological effect and has generally been stopped much closer to the operation in published ATC surgical series [12,13].

The exact timing should be decided jointly by the surgeon and medical oncologist. Patients should never stop either medicine themselves simply because an operation has been scheduled.

Why the Interruption Should Not Be Longer Than Necessary

ATC can regain momentum quickly when an effective systemic treatment is withdrawn. For this reason, specialist centres have tried to minimise the period without BRAF and MEK inhibition [12,13].

When I explain this to a patient, I describe surgery as part of the targeted-treatment pathway rather than the end of it. Even if the surgeon successfully removes all visible neck disease, microscopic or distant cancer cells may remain.

When Is Treatment Restarted?

Dabrafenib and trametinib may be restarted after surgery once the medical team is satisfied with postoperative recovery and wound healing. Published institutional protocols have restarted BRAF/MEK therapy within the early postoperative period when clinically safe, although the exact timing varies according to complications, healing and plans for radiation [12,13].

A significant wound problem, infection, bleeding or another postoperative complication may require a longer interruption.

What Does the Surgical Specimen Tell Us?

The removed tumour should be examined carefully by the pathologist. The specimen may show viable ATC, extensive treatment-related necrosis or, occasionally, a very deep pathological response.

This information helps the multidisciplinary team decide what should happen next. The questions are whether targeted therapy should continue, whether postoperative radiation is needed and how closely the patient should be monitored.

The important point is that surgery does not automatically replace dabrafenib and trametinib. In patients who reached surgery because targeted therapy successfully controlled their disease, systemic treatment may still remain an important part of the overall strategy [1,12,13].

Do Patients Still Need Radiation After the Tumour Responds?

A strong response to dabrafenib and trametinib does not automatically remove the need for radiation. Targeted therapy can control disease throughout the body, while radiation is mainly used to strengthen control in the neck or treat specific metastatic sites. The two approaches therefore have different but complementary roles [1,12,13,17].

The final decision depends on whether surgery becomes possible, whether microscopic or visible tumour remains and whether the neck disease still threatens the airway, oesophagus or major blood vessels.

Radiation After Surgery

Even after an R0 or R1 resection, postoperative radiation may be considered because anaplastic thyroid cancer has a high risk of returning in the neck.

An R0 operation removes all visible disease with clear microscopic margins, but it cannot guarantee that every cancer cell has been eliminated. An R1 operation leaves possible microscopic disease at the surgical margin, making additional local treatment particularly important.

When I explain this to a patient, I describe surgery as removing the main tumour burden and radiation as helping control cancer cells that may remain in the surgical area.

Radiation When Surgery Remains Impossible

Some tumours respond to dabrafenib and trametinib but still cannot be removed safely. The tumour may remain attached to the carotid artery, trachea, oesophagus or deep neck structures.

In this situation, radiation may be used to improve locoregional control, reduce the risk of renewed neck progression or relieve symptoms. Targeted therapy may continue before or after radiation according to the multidisciplinary plan.

The treatment sequence must be individualised because combining radiation with targeted medicines may increase certain toxicities. The medical oncologist and radiation oncologist should therefore decide whether treatment should continue, pause or be modified around radiation.

Radiation for Metastatic Disease

A patient with stage IVC ATC may experience good systemic control but still have one painful or threatening metastatic lesion. Radiation can be used for bone pain, spinal compression, brain metastases or another limited site requiring rapid local treatment.

This does not always mean that dabrafenib and trametinib have completely failed. If most disease remains controlled, the team may treat the resistant or symptomatic site locally and reassess the wider systemic strategy.

Why Response Should Lead to a New Treatment Review

If your tumour shrinks, the next step should not be to continue the same plan without discussion. The team should ask whether surgery has become possible, whether radiation could strengthen neck control and whether distant disease requires separate treatment.

A good targeted-therapy response creates an opportunity. The purpose of multidisciplinary care is to use that opportunity before the tumour develops resistance or begins growing again.

What Tests Should Be Done Before Starting Dabrafenib and Trametinib?

Before dabrafenib and trametinib are started, the oncology team should confirm that the tumour is BRAF V600E-positive and establish a clear baseline for monitoring treatment safety. These tests do not predict with certainty whether the tumour will respond, but they help doctors identify medical problems that could increase the risk of complications [3,4].

The exact assessment may vary according to the patient’s age, symptoms, previous treatments and other medical conditions.

Confirming the BRAF V600E Mutation

The molecular report should clearly confirm BRAF V600E. An inconclusive, failed or inadequate result should not be treated as a confirmed positive finding.

The team should also review the original pathology to ensure that the diagnosis is anaplastic thyroid carcinoma. Broader molecular profiling may be arranged alongside rapid BRAF testing because additional alterations can influence future treatment options.

Blood Tests

Baseline blood tests commonly include a complete blood count, kidney function, liver function, electrolytes and blood glucose.

These results help the team identify anaemia, infection risk, dehydration, organ dysfunction or uncontrolled diabetes before treatment begins. They also provide a comparison point if abnormalities develop later.

Patients with diabetes may require more frequent glucose monitoring because dabrafenib and trametinib can worsen hyperglycaemia in some cases [3,4].

Heart Assessment

Trametinib can reduce the heart’s pumping function. A baseline echocardiogram or another measurement of left ventricular ejection fraction is therefore important before treatment [4].

The patient should tell the oncologist about previous heart failure, chest pain, rhythm problems, swelling of the legs or unexplained breathlessness. If cardiac function is already reduced, the treatment plan and monitoring schedule may need modification.

Eye and Vision History

The oncology team should ask about retinal disease, previous eye inflammation, blurred vision and other significant visual problems. A formal eye examination may be arranged when symptoms or previous conditions create concern.

New visual changes during treatment require urgent assessment because trametinib can cause retinal and other ocular complications [4].

Medication and Supplement Review

Every prescription medicine, over-the-counter product, vitamin, herbal preparation and Ayurvedic formulation should be reviewed before therapy begins.

Dabrafenib can affect the metabolism of other medicines, while some drugs and supplements may alter dabrafenib exposure. The pharmacist should also check anticoagulants, diabetes medicines, steroids and hormonal treatments carefully [3].

Baseline Imaging and Clinical Condition

Recent imaging should document the tumour’s size, airway involvement, lymph nodes and distant metastases. Doctors also assess breathing, swallowing, voice, body weight, nutritional status and performance status.

For patients who may later become surgical candidates, these baseline findings are essential. They allow the team to determine whether targeted therapy has changed the tumour’s size, anatomical relationships and resectability.

The purpose of baseline testing is not to delay treatment. It is to begin rapidly with enough information to manage risks, recognise toxicity and measure whether the treatment is achieving its intended goal.

How Is Treatment Monitored Month by Month?

Dabrafenib and trametinib require regular monitoring because the oncology team must assess two things at the same time: whether the cancer is responding and whether the medicines are causing harmful side effects. Monitoring is usually more frequent during the first weeks, when fever, dehydration, skin reactions or other early problems may appear [3,4].

There is no identical monthly schedule for every patient. The timing depends on tumour urgency, symptoms, treatment tolerance and whether the medicines are being used to prepare the patient for surgery.

Clinical Review During the First Weeks

Soon after treatment begins, the team should reassess breathing, swallowing, neck swelling, voice, pain, body temperature and ability to maintain food and fluids.

If you have an airway-threatening tumour, clinical review may be required much earlier than a routine monthly appointment. Worsening breathlessness, stridor, inability to swallow liquids or rapidly increasing neck swelling requires urgent assessment rather than waiting for the next scheduled review.

I would also ask whether the patient is taking every dose correctly, following the fasting instructions and experiencing any difficulty swallowing the medicines.

Regular Blood Tests

Blood monitoring may include complete blood count, liver and kidney function, electrolytes and blood glucose. These tests help detect dehydration, organ dysfunction, infection, hyperglycaemia or other treatment-related changes.

Patients who develop repeated fever, vomiting or diarrhoea may need earlier blood tests because fluid loss can affect kidney function and electrolyte balance [3,4].

Heart Monitoring

Trametinib can reduce the heart’s pumping function. Left ventricular ejection fraction is generally assessed before treatment, after approximately one month and then at regular intervals during therapy [4].

New breathlessness, ankle swelling, unusual fatigue or chest discomfort should be reported promptly. These symptoms may result from several causes in an ATC patient, so they require proper evaluation rather than assumption.

Eye, Skin and Fever Monitoring

The patient should report blurred vision, flashes, floaters or sudden changes in eyesight. Persistent or severe rash, blistering, painful skin changes or mouth sores also require review.

Temperature should be monitored whenever the patient feels unwell. Fever may be treatment-related, but infection must still be considered, especially when chills, low blood pressure, cough, urinary symptoms or dehydration are present [3,4].

Imaging and Response Assessment

Imaging is repeated according to the treatment objective. A patient receiving targeted therapy to make an unresectable tumour operable may need earlier scans than someone receiving long-term treatment for stable metastatic disease.

The team compares the neck tumour, lymph nodes and distant metastases with baseline imaging. A good response should lead to a new discussion about surgery, radiation or continued systemic treatment rather than simple continuation without reassessment [10].

Month-by-month monitoring is therefore not only a safety exercise. It helps the team recognise benefit early, manage toxicity before it becomes severe and use the treatment response to guide the next major decision.

Fever During Dabrafenib and Trametinib: When Is It Serious?

Fever is one of the most important side effects associated with dabrafenib and trametinib. It may occur as an isolated rise in temperature or together with chills, shaking, weakness, dehydration or low blood pressure. In some patients, febrile episodes recur after treatment is restarted [3,4,10].

Most episodes can be managed safely when they are reported early. However, fever should never be ignored because infection, aspiration pneumonia and treatment-related pyrexia can appear similar in a patient with anaplastic thyroid cancer.

What Is Treatment-Related Pyrexia?

Pyrexia means an abnormal rise in body temperature. With dabrafenib and trametinib, it may occur even when no bacterial or viral infection is found.

The patient may experience a temperature of 38°C or higher, chills, sweating, body pain, dizziness or unusual fatigue. Some people develop dehydration or reduced blood pressure, particularly when fever is accompanied by vomiting, diarrhoea or poor fluid intake [3,4].

I explain to patients that treatment-related fever is recognised and often manageable, but it should not be diagnosed at home without informing the oncology team.

Why Infection Must Still Be Considered

A patient with ATC may have swallowing impairment, aspiration, a feeding tube, recent surgery or reduced general strength. These factors can increase the risk of pneumonia and other infections.

Fever with cough, breathing difficulty, painful urination, confusion, severe weakness or localised pain requires prompt medical assessment. Blood tests, urine tests, chest imaging or cultures may be needed according to the symptoms.

Doctors should not automatically assume that every fever is caused by dabrafenib and trametinib.

What Should the Patient Do When Fever Begins?

The patient should check and record the temperature and contact the oncology team according to the written fever plan. The treating team may advise temporarily withholding dabrafenib and trametinib while the cause is assessed [3,4].

You should not repeatedly stop and restart the medicines without medical guidance. The timing of restarting treatment depends on whether the fever has resolved, whether infection was excluded and whether complications such as dehydration or kidney dysfunction occurred.

Adequate fluids may be helpful when swallowing is safe, but a patient who cannot maintain hydration may require intravenous fluids.

When Is Hospital Assessment Needed?

Urgent assessment is especially important when fever occurs with severe chills, fainting, confusion, reduced urine output, low blood pressure, worsening breathlessness or inability to drink.

Persistent fever, recurrent episodes or symptoms continuing after treatment interruption also require medical review. The team may consider laboratory testing, infection treatment, dose modification or additional medicines for recurrent pyrexia.

A written fever plan should be provided before treatment begins. It should explain whom to contact, when to withhold treatment and which symptoms require immediate hospital care. Early reporting usually makes fever safer and easier to manage.

Common Side Effects of Dabrafenib and Trametinib

Dabrafenib and trametinib can cause side effects even when the treatment is controlling the cancer. The most commonly reported problems include fever, chills, fatigue, skin rash, nausea, reduced appetite, diarrhoea, headache, muscle or joint pain and swelling of the hands or feet [3,4,10].

The severity varies considerably. One patient may continue normal daily activities with mild symptoms, while another may require temporary treatment interruption or dose reduction.

Why Early Reporting Matters

Patients sometimes avoid reporting side effects because they fear that the oncology team will permanently stop an effective treatment. In practice, early reporting often helps the team manage the problem before it becomes severe.

Temporary interruption, supportive treatment or dose modification does not automatically mean that dabrafenib and trametinib have failed. These measures are often used to preserve safety while allowing treatment to continue.

You should tell the team if side effects interfere with eating, drinking, walking, sleeping or taking the prescribed doses correctly. Persistent diarrhoea, repeated vomiting or reduced appetite can quickly lead to dehydration and weight loss, particularly in someone who already has swallowing difficulty.

Skin and General Symptoms

A mild rash may be manageable, but rapidly spreading redness, painful skin, blistering or sores involving the mouth require urgent assessment. Swelling should also be reviewed when it appears suddenly or occurs with breathlessness.

When I discuss side effects with a patient, I emphasise that symptoms should not be judged only by how uncomfortable they feel. A seemingly simple problem such as fever or diarrhoea may affect blood pressure, kidney function and hydration if it continues.

The safest approach is to report new or worsening symptoms promptly and allow the oncology team to decide whether treatment can continue unchanged.

Serious Side Effects Patients and Families Should Recognise

Most patients will not experience every serious complication, but families should know which symptoms require urgent medical review. Dabrafenib and trametinib can affect the heart, eyes, lungs, skin, blood vessels, blood glucose and bleeding risk [3,4].

Table : Side Effects and When to Seek Help

Heart Problems

Trametinib can reduce the heart’s pumping function. New breathlessness, swelling of the ankles, chest discomfort or unusual exhaustion should be reported promptly.

These symptoms can also result from lung metastases, infection, anaemia or blood clots. Medical assessment is therefore needed rather than assuming that the medicine is responsible.

Eye and Vision Problems

Blurred vision, flashes, floaters, loss of part of the visual field or sudden reduction in sight requires urgent eye assessment. Retinal complications and eye inflammation are recognised risks of MEK inhibition [4].

Patients should not wait for a routine appointment if vision changes suddenly.

Bleeding, Blood Clots and Lung Symptoms

Unexplained bruising, black stools, vomiting blood or coughing blood may indicate bleeding. Sudden chest pain, acute breathlessness or swelling of one leg may suggest a blood clot.

A new persistent cough, falling oxygen level or unexplained breathing difficulty may result from infection, tumour progression, pulmonary embolism or drug-related lung inflammation. Each of these possibilities requires prompt evaluation.

Severe Skin Reactions and High Blood Sugar

Painful widespread rash, blistering, skin peeling or sores affecting the mouth or eyes should be treated as urgent warning signs.

Patients with diabetes should monitor blood glucose closely because treatment can worsen hyperglycaemia. Excessive thirst, frequent urination, confusion or severe weakness may indicate significantly elevated blood sugar [3,4].

Which Symptoms Require Immediate Emergency Assessment?

Some emergency symptoms may come from the cancer itself, while others may be related to treatment. Patients and relatives should know the difference is not always obvious, so they should seek urgent help rather than trying to diagnose the cause at home.

Airway and Neck Emergencies

Stridor, rapidly worsening breathlessness, inability to lie flat, sudden neck enlargement or severe difficulty swallowing liquids requires immediate assessment. These symptoms may indicate increasing airway compression, bleeding into the tumour or aspiration.

Dabrafenib and trametinib should not be given extra time to work when the airway appears unstable. Emergency airway management may still be necessary even after targeted therapy has begun [1].

Other Emergency Warning Signs

Sudden loss of vision, fainting, confusion, severe dehydration, reduced urine output, chest pain, coughing blood or sudden swelling of a limb also requires urgent medical attention.

A high fever accompanied by shaking chills, low blood pressure, severe weakness or inability to drink may need hospital evaluation. The cause may be treatment-related pyrexia, infection or both.

When I counsel a family, I advise them to keep the oncology contact numbers and nearest emergency facility readily available. ATC can change quickly, and early assessment is safer than waiting for symptoms to settle without medical guidance.

What Does the First Scan After Starting Treatment Tell Us?

Table: Understanding the First Treatment-Response Scan

The first response scan is an important decision point. It should not be treated only as a report stating that the tumour is smaller, stable or larger. The result should be used to decide what happens next.

A Major Response

If the tumour has reduced substantially, the team should reconsider surgery and radiation rather than simply continuing treatment without review.

The surgeon should assess whether the tumour has moved away from the carotid arteries, trachea, oesophagus or mediastinal structures. Distant metastases should also be reviewed to confirm whether the response is occurring throughout the body [12,13].

A Partial Response

A partial response may still provide major clinical benefit. The patient may breathe or swallow more easily even though visible disease remains.

The team may continue treatment for further shrinkage, plan radiation or reconsider surgery according to the anatomy and treatment goal.

Stable Disease

Stable disease means that the cancer has not changed enough to qualify as response or progression. In rapidly growing ATC, temporary stability can be valuable.

However, stability may not be sufficient when the tumour still threatens the airway or remains unsuitable for meaningful local treatment. The clinical context matters more than the label alone.

Progressive Disease

If the cancer has enlarged or new lesions have appeared, the team should confirm that doses were taken correctly, review treatment interruptions and reassess the molecular findings.

The scan should answer not only whether treatment is working, but also whether the original treatment objective remains achievable.

Why Can Dabrafenib and Trametinib Eventually Stop Working?

Some BRAF V600E-positive tumours fail to respond from the beginning. This is called primary resistance. Other tumours shrink initially but later begin growing again, which is known as acquired resistance.

Primary Resistance

BRAF V600E may be an important driver without being the tumour’s only survival mechanism. Additional mutations and alternative signalling pathways may allow cancer cells to continue growing despite BRAF and MEK inhibition [7,8,20].

This helps explain why a positive BRAF result does not guarantee a response.

Acquired Resistance

During treatment, some cancer cells may develop or select molecular changes that restore growth signalling. Secondary RAS mutations have been documented in thyroid cancers progressing after BRAF-directed treatment [19].

The tumour may also activate alternative pathways or contain different cancer-cell groups with different levels of treatment sensitivity. Most disease may remain controlled while one resistant population begins to grow.

When I explain resistance to a patient, I describe it as biological adaptation rather than something the patient caused. Correct dosing remains important, but progression can occur even when treatment has been taken perfectly.

Resistance does not always mean that every tumour site has stopped responding. This distinction becomes especially important when only one or a few lesions are growing.

What Is Oligoprogression and What Happens After Progression?

Oligoprogression means that one or a small number of tumour sites begin growing while most of the cancer remains controlled. For example, the neck tumour and most lung metastases may remain smaller while one lung lesion enlarges.

Treating a Limited Resistant Site

In selected patients, surgery or focused radiation may be used to control the progressing site while dabrafenib and trametinib continue to control the remaining disease.

This is not a standard solution for every patient. The decision depends on the number of growing lesions, their location, the duration of previous benefit and the patient’s general condition.

When Progression Is More Widespread

If several tumour sites are progressing, the team should confirm true progression and review whether treatment interruptions, poor absorption or interactions may have reduced drug exposure.

Repeat biopsy or circulating tumour DNA testing may help identify new resistance mechanisms. Broader molecular profiling may reveal another actionable alteration or support referral to a clinical trial [2,6,19,20].

Immunotherapy, alternative targeted strategies, radiation, surgery for selected symptoms and supportive care may all be considered according to the clinical situation.

Progression therefore requires a new treatment plan, not an automatic assumption that no further care is possible. The next step depends on whether resistance is limited or widespread, whether another molecular target is present and which problems are most urgent for the patient.

Should Pembrolizumab Be Added to Dabrafenib and Trametinib?

Pembrolizumab is an immunotherapy medicine that helps the immune system recognise and attack cancer cells. Dabrafenib and trametinib act differently because they directly block the BRAF–MEK growth pathway. Combining these approaches may provide broader tumour control, but pembrolizumab is not automatically required for every patient with BRAF V600E-positive anaplastic thyroid cancer.

Dabrafenib and trametinib remain the established molecularly targeted combination for this group. The evidence supporting the addition of pembrolizumab is promising but less certain because it mainly comes from retrospective and nonrandomised studies [2,16].

What the Available Study Found

A 2024 retrospective study evaluated patients with BRAF V600E-mutated ATC who received dabrafenib and trametinib, with some also receiving pembrolizumab. The outcomes appeared encouraging in the pembrolizumab group, but the study could not prove that pembrolizumab caused the entire difference [16].

Patients were not randomly assigned to treatment, and pembrolizumab was not always started at the same point. Differences in disease burden, general health, surgery, radiation and previous treatment may also have affected the results.

For this reason, the study supports further consideration and research rather than routine triplet therapy for every patient.

What Current Guidance Means in Practice

Current systemic-treatment guidance strongly supports dabrafenib and trametinib for BRAF V600E-mutated ATC. Pembrolizumab may be considered in selected cases, but the evidence supporting its addition is weaker than the evidence for BRAF and MEK inhibition alone [2].

When I discuss this option with a patient, I would first ask why pembrolizumab is being added. The reason may be extensive metastatic disease, an incomplete response, progression risk, high PD-L1 expression or a specialist team’s decision to use a combined approach.

Who May Not Be a Suitable Candidate?

Pembrolizumab can cause immune-related inflammation affecting the lungs, liver, bowel, thyroid, adrenal glands, skin and other organs. Patients with active autoimmune disease, organ transplantation or previous severe immunotherapy toxicity may require particular caution.

You should understand that adding a third medicine may increase treatment complexity. It requires monitoring for both targeted-therapy toxicity and immune-related complications.

The decision should therefore be individualised. Pembrolizumab may strengthen treatment in selected patients, but it should not be presented as essential for every BRAF V600E-positive ATC case.

Dabrafenib and Trametinib in Metastatic Stage IVC ATC

Stage IVC anaplastic thyroid cancer means that the disease has spread beyond the neck to distant organs. Dabrafenib and trametinib can be particularly important in this setting because they act systemically and may control several tumour sites at the same time [1,2,10].

The objective is usually to reduce the total cancer burden, preserve organ function, improve symptoms and delay further progression. Treatment may also create an opportunity to address the most threatening disease sites with surgery or radiation.

Lung Metastases

The lungs are a common site of distant spread. Multiple small lung metastases may respond together with the neck tumour, but the depth of response can vary between lesions.

Breathlessness should not automatically be attributed to lung metastases. Infection, aspiration, blood clots, treatment-related lung inflammation and heart dysfunction may produce similar symptoms.

Bone and Brain Metastases

Bone metastases may cause pain, fracture risk or spinal-cord compression. Radiation, surgery or bone-directed supportive treatment may be required even when dabrafenib and trametinib are controlling disease elsewhere.

Brain metastases require individual assessment because the size, number, symptoms and location of lesions affect treatment. Focused radiation, surgery, steroids or other measures may be needed alongside systemic therapy.

Why the Neck Tumour Still Matters

A patient may have widespread metastatic disease but remain at immediate risk from the neck tumour. Tracheal compression, bleeding, severe swallowing difficulty or invasion of major structures can become more urgent than distant disease.

For this reason, stage IVC treatment should not focus only on scans of the lungs or other organs. The team must continue monitoring the airway, swallowing, voice and local neck anatomy.

How Benefit Is Assessed

A meaningful benefit may include tumour shrinkage, stable disease, improved breathing, reduced pain, better food intake or decreased need for supportive treatment. The goal is not always complete disappearance of every lesion.

If you have stage IVC disease, the oncology team should explain whether the main objective is long-term systemic control, rapid symptom relief, preparation for local treatment or a combination of these aims.

What If the Neck Tumour Shrinks but the Metastases Do Not?

Different tumour sites within the same patient may respond differently to dabrafenib and trametinib. The neck tumour may shrink while one lung, bone or other metastatic lesion remains stable or grows. This is known as a mixed or heterogeneous response.

Such a result does not always mean that the treatment has failed everywhere. It may indicate that different tumour-cell populations are present in different sites [10,19,20].

Why Mixed Responses Occur

BRAF V600E may be present throughout the cancer, but additional mutations can differ between tumour deposits. One lesion may remain dependent on BRAF signalling, while another may activate an alternative growth pathway.

Resistance can also develop in one tumour site earlier than in others. Secondary molecular changes, including RAS alterations, have been identified after progression on BRAF-directed treatment [19].

What the Medical Team Should Review

Doctors should confirm that the growing lesion represents true progression rather than infection, inflammation, treatment-related change or a second disease. In selected cases, biopsy of the resistant lesion may be helpful.

The team should also compare every disease site rather than judging treatment from the neck tumour alone. A major neck response can be clinically valuable, but uncontrolled metastatic disease may still require a change in strategy.

Can the Growing Lesion Be Treated Separately?

If only one or a few lesions are progressing, focused radiation or surgery may sometimes control those sites while dabrafenib and trametinib continue to suppress the rest of the cancer.

If progression is widespread, repeat molecular profiling, circulating tumour DNA, immunotherapy, another targeted strategy or a clinical trial may be considered.

When I explain a mixed response, I tell the patient that the treatment decision should not be reduced to “continue” or “stop” based on one lesion. The team must determine how much disease remains controlled, how dangerous the resistant site is and whether local treatment can preserve the wider benefit.

FAQs

Reference

1. American Thyroid Association ATC Guideline

Bible, K. C., Kebebew, E., Brierley, J., Brito, J. P., Cabanillas, M. E., Clark, T. J., Jr., Di Cristofano, A., Foote, R., Giordano, T., Kasperbauer, J., Newbold, K., Nikiforov, Y. E., Randolph, G., Rosenthal, M. S., Sawka, A. M., Shah, M., Shaha, A., Smallridge, R., Wong-Clark, C. K., et al. (2021). 2021 American Thyroid Association guidelines for management of patients with anaplastic thyroid cancer. Thyroid, 31(3), 337–386.
https://pmc.ncbi.nlm.nih.gov/articles/PMC8349723/
Used for: This is the fundamental ATC management guideline for diagnosis, urgent airway assessment, staging, molecular testing, surgery, radiation, systemic therapy, multidisciplinary decision-making and supportive care. It will anchor almost every early clinical section of the article.

2. 2026 ASCO Systemic Treatment Guideline

Saba, N. F., Ismaila, N., Adkins, D., Agrawal, N., Akhave, N., Blomain, E. S., Cabanillas, M. E., Chen, A., Galloway, T. J., Harada, G., Li, D., Noureldine, S. I., Scharpf, J., Sun, L. L., Tang, M., Wirth, L., Worden, F., Zandberg, D. P., & Beadle, B. M. (2026). Systemic treatment of thyroid cancer: ASCO guideline. Journal of Clinical Oncology.
https://pubmed.ncbi.nlm.nih.gov/41921121/
Used for: This is the most important current systemic-treatment guideline. It supports dabrafenib plus trametinib as BRAF-directed treatment in BRAF V600E-mutated ATC and informs treatment after progression and the conditional consideration of adding checkpoint inhibition.

3. Current TAFINLAR Prescribing Information

Novartis Pharmaceuticals Corporation. (2026). TAFINLAR (dabrafenib): Full prescribing information. DailyMed, U.S. National Library of Medicine.
https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=fee1e6b1-e1a5-4254-9f2e-a70e0f8dbdea
Used for: Primary source for the FDA-labeled ATC indication, dabrafenib dose, administration, BRAF V600E confirmation, dose modification, pharmacology, drug interactions, safety warnings, pyrexia and clinical-study data.

4. Current MEKINIST Prescribing Information

Novartis Pharmaceuticals Corporation. (2026). MEKINIST (trametinib): Full prescribing information. DailyMed, U.S. National Library of Medicine.
https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=0002ad27-779d-42ab-83b5-bc65453412a1
Used for: Primary source for the trametinib 2-mg once-daily adult dose, administration, duration, cardiac monitoring, retinal/ocular toxicity, hemorrhage, thrombosis, pyrexia, dose modifications and other serious adverse effects. The label includes a major safety update dated May 2026.

5. FDA-Approved Companion Diagnostic for BRAF V600E ATC

U.S. Food and Drug Administration. (2023). Oncomine Dx Target Test, PMA P160045/S025.
https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpma/pma.cfm?id=P160045S025
Used for: FDA evidence that the Oncomine Dx Target Test is approved as a companion diagnostic for identifying BRAF V600E-positive ATC patients for dabrafenib and trametinib. The FDA decision date for this expanded indication was September 29, 2023.

6. European Consensus on Molecular Testing

Ryška, A., et al. (2025). Molecular predictive biomarker testing in advanced thyroid cancer—A European consensus. European Thyroid Journal, 14(4), e250024.
https://pubmed.ncbi.nlm.nih.gov/40540622/
Used for: Current molecular-testing strategy, including rapid/reflex BRAF assessment in ATC and broader DNA/RNA next-generation sequencing when BRAF V600E is absent or additional actionable alterations need to be identified.

7. Molecular Biology of Anaplastic Thyroid Cancer

Landa, I., Ibrahimpasic, T., Boucai, L., Sinha, R., Knauf, J. A., Shah, R. H., Dogan, S., Ricarte-Filho, J. C., Krishnamoorthy, G. P., Xu, B., Schultz, N., Berger, M. F., Sander, C., Taylor, B. S., Ghossein, R., Ganly, I., & Fagin, J. A. (2016). Genomic and transcriptomic hallmarks of poorly differentiated and anaplastic thyroid cancers. Journal of Clinical Investigation, 126(3), 1052–1066.
https://pmc.ncbi.nlm.nih.gov/articles/PMC4767360/
Used for: Explains the genomic evolution of ATC and the biological roles of BRAF, TP53, TERT and other molecular alterations. This will support the patient-friendly explanation of why BRAF V600E can become a therapeutic target.

8. Large Genomic Study of Advanced Thyroid Cancer

Pozdeyev, N., Gay, L. M., Sokol, E. S., Hartmaier, R., Deaver, K. E., Davis, S., French, J. D., Borre, P. V., LaBarbera, D. V., Tan, A. C., Schweppe, R. E., Fishbein, L., Ross, J. S., Haugen, B. R., & Bowles, D. W. (2018). Genetic analysis of 779 advanced differentiated and anaplastic thyroid cancers. Clinical Cancer Research, 24(13), 3059–3068.
https://pmc.ncbi.nlm.nih.gov/articles/PMC6030480/
Used for: Large-scale genomic evidence showing the diversity and frequency of potentially actionable molecular alterations in advanced thyroid cancer, supporting comprehensive molecular profiling rather than BRAF testing alone.

9. Original Prospective Dabrafenib–Trametinib ATC Study

Subbiah, V., Kreitman, R. J., Wainberg, Z. A., Cho, J. Y., Schellens, J. H. M., Soria, J. C., Wen, P. Y., Zielinski, C., Cabanillas, M. E., Urbanowitz, G., Mookerjee, B., Wang, D., Rangwala, F., & Keam, B. (2018). Dabrafenib and trametinib treatment in patients with locally advanced or metastatic BRAF V600-mutant anaplastic thyroid cancer. Journal of Clinical Oncology, 36(1), 7–13.
https://pmc.ncbi.nlm.nih.gov/articles/PMC5791845/
Used for: The original prospective clinical evidence establishing substantial antitumour activity of combined BRAF and MEK inhibition in BRAF-mutated ATC. It will be used for initial response evidence, response timing and safety.

10. Updated ROAR ATC Analysis

Subbiah, V., Kreitman, R. J., Wainberg, Z. A., Cho, J. Y., Schellens, J. H. M., Soria, J. C., Wen, P. Y., Zielinski, C. C., Cabanillas, M. E., Boran, A., Ilankumaran, P., Burgess, P., Romero Salas, T., & Keam, B. (2022). Dabrafenib plus trametinib in patients with BRAF V600E-mutant anaplastic thyroid cancer: Updated analysis from the phase II ROAR basket study. Annals of Oncology, 33(4), 406–415.
https://pmc.ncbi.nlm.nih.gov/articles/PMC9338780/
Used for: This will be our principal efficacy study. It provides updated objective response, duration of response, progression-free survival and overall-survival outcomes in 36 patients with BRAF V600E-mutated ATC.

11. Final Broader ROAR Basket-Trial Report

Subbiah, V., et al. (2023). Dabrafenib plus trametinib in BRAF V600E-mutated rare cancers: The phase 2 ROAR trial. Nature Medicine, 29, 1103–1112.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10202803/
Used for: Provides mature context for the ROAR basket trial and reinforces the efficacy and safety of BRAF/MEK targeting across BRAF V600E-driven rare malignancies, including ATC.

12. Original Neoadjuvant Surgical-Conversion Series

Wang, J. R., Zafereo, M. E., Dadu, R., Ferrarotto, R., Busaidy, N. L., Lu, C., Ahmed, S., Gule-Monroe, M. K., Williams, M. D., Sturgis, E. M., Goepfert, R. P., Gross, N. D., Lai, S. Y., Gunn, G. B., Phan, J., Rosenthal, D. I., Fuller, C. D., Morrison, W. H., Iyer, P., et al. (2019). Complete surgical resection following neoadjuvant dabrafenib plus trametinib in BRAF V600E-mutated anaplastic thyroid carcinoma. Thyroid, 29(8), 1036–1043.
https://pmc.ncbi.nlm.nih.gov/articles/PMC6707029/
Used for: Landmark proof-of-concept showing that six carefully selected patients with initially unresectable BRAF V600E-positive ATC underwent complete surgical resection after neoadjuvant dabrafenib/trametinib. This is crucial for the “Can inoperable ATC become operable?” section.

13. Larger Surgical Cohort After BRAF-Directed Therapy

Zhao, X., Wang, J. R., Dadu, R., Busaidy, N. L., Xu, L., Learned, K. O., Chasen, N. N., Vu, T., Maniakas, A., Eguia, A. A., Diersing, J., Gross, N. D., Goepfert, R. P., Lai, S. Y., Hofmann, M. C., Ferrarotto, R., Lu, C., Gunn, G. B., Spiotto, M. T., et al. (2023). Surgery after BRAF-directed therapy is associated with improved survival in BRAF V600E-mutant anaplastic thyroid cancer: A single-center retrospective cohort study. Thyroid, 33(4), 484–491.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10122263/
Used for: Provides larger real-world evidence that neoadjuvant BRAF-directed therapy can decrease tumour burden and surgical morbidity and allow resection in selected responders. We will explicitly acknowledge the retrospective design and selection bias.

14. Newer Mutation-Based Neoadjuvant Experience

Wächter, S., Bartsch, D. K., Riera Knorrenschild, J., Pehl, A., Eilsberger, F., Pfestroff, A., Luster, M., Holzer, K., Neubauer, A., & Maurer, E. (2025). Mutation-based, neoadjuvant treatment for advanced anaplastic thyroid carcinoma. Frontiers in Endocrinology, 16, 1619875.
https://pmc.ncbi.nlm.nih.gov/articles/PMC12414790/
Used for: Contemporary experience with mutation-guided neoadjuvant therapy and surgical restaging. It is valuable because it also demonstrates limitations and complications: only two patients in this small series had BRAF V600E, responses were not universal, and fistulas occurred in some patients.

15. Systematic Review and Meta-Analysis of Dabrafenib–Trametinib in ATC

Limonard, A., Zhang, J., Inchley, J., Yap, A., Lu, V. Y. Z., & Tolley, N. (2025). Systematic review and meta-analysis of the efficacy of dabrafenib and trametinib in the multi-modal treatment of anaplastic thyroid cancer. The Journal of Laryngology & Otology, 139(6), 441–450.
https://pubmed.ncbi.nlm.nih.gov/39658800/
Used for: Synthesizes published dabrafenib/trametinib outcomes and helps us discuss the totality of evidence while highlighting limitations created by small samples, retrospective cohorts and patient selection.

16. Dabrafenib–Trametinib Plus Pembrolizumab Study

Hamidi, S., Iyer, P. C., Dadu, R., Gule-Monroe, M. K., Maniakas, A., Zafereo, M. E., Wang, J. R., Busaidy, N. L., & Cabanillas, M. E. (2024). Checkpoint inhibition in addition to dabrafenib/trametinib for BRAF V600E-mutated anaplastic thyroid carcinoma. Thyroid, 34(3), 336–346.
https://pubmed.ncbi.nlm.nih.gov/38226606/
Used for: Retrospective evidence examining addition of pembrolizumab to dabrafenib/trametinib. The study reported encouraging survival differences, but because it was nonrandomized and retrospective, it cannot establish that every BRAF V600E-positive ATC patient should receive triplet therapy.

17. Modern ATC Survival and Multimodal Treatment

Maniakas, A., Dadu, R., Busaidy, N. L., Wang, J. R., Ferrarotto, R., Lu, C., Williams, M. D., Gunn, G. B., Hofmann, M. C., Cote, G., Sperling, J., Gross, N. D., Sturgis, E. M., Goepfert, R. P., Lai, S. Y., Cabanillas, M. E., & Zafereo, M. (2020). Evaluation of overall survival in patients with anaplastic thyroid carcinoma, 2000–2019. JAMA Oncology, 6(9), 1397–1404.
https://pmc.ncbi.nlm.nih.gov/articles/PMC7411939/
Used for: A 479-patient institutional cohort showing substantial improvement in ATC survival over successive treatment eras and associations between targeted therapy, immunotherapy, neoadjuvant BRAF treatment, surgery and improved outcomes. Because it is observational, it demonstrates association rather than proof of causation.

18. Targeted Therapy Plus Atezolizumab Trial

Cabanillas, M. E., Dadu, R., Ferrarotto, R., Gule-Monroe, M., Liu, S., Fellman, B., Williams, M. D., Zafereo, M., Wang, J. R., Lu, C., Ning, M., McKinley, B. A., Woodman, S. E., Duose, D., Gunn, G. B., Busaidy, N. L., et al. (2024). Anti-programmed death ligand 1 plus targeted therapy in anaplastic thyroid carcinoma: A nonrandomized clinical trial. JAMA Oncology, 10(12), 1672–1680.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11581602/
Used for: Prospective evidence supporting the concept of combining mutation-directed treatment with checkpoint inhibition. Importantly, the BRAF V600E cohort received vemurafenib + cobimetinib + atezolizumab, so we will not misrepresent this as a dabrafenib/trametinib trial.

19. Acquired Resistance Through Secondary RAS Mutations

Cabanillas, M. E., Dadu, R., Iyer, P., Wanland, K. B., Busaidy, N. L., Ying, A., Gule-Monroe, M., Wang, J. R., Zafereo, M., & Hofmann, M. C. (2020). Acquired secondary RAS mutation in BRAF V600E-mutated thyroid cancer patients treated with BRAF inhibitors. Thyroid, 30(9), 1288–1296.
https://pmc.ncbi.nlm.nih.gov/articles/PMC7869871/
Used for: Direct molecular evidence of acquired resistance. Progressive tumour samples or liquid biopsy identified new KRAS or NRAS alterations in patients after BRAF-directed treatment. This will strengthen the resistance, re-biopsy and ctDNA sections.

20. Somatic Mutations and Outcomes in ATC

Wang, J. R., Montierth, M., Xu, L., Goswami, M., Zhao, X., Cote, G., Wang, W., Iyer, P., Dadu, R., Busaidy, N. L., Lai, S. Y., Gross, N. D., Ferrarotto, R., Lu, C., Gunn, G. B., Williams, M. D., Routbort, M., Zafereo, M. E., & Cabanillas, M. E. (2022). Impact of somatic mutations on survival outcomes in patients with anaplastic thyroid carcinoma. JCO Precision Oncology, 6, e2100504.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10530586/
Used for: Demonstrates that ATC biology is not determined by BRAF alone. In BRAF V600E-mutated patients receiving BRAF-directed therapy, TP53 mutation was associated with shorter progression-free survival, supporting our discussion of tumour heterogeneity and variable treatment response.

21. Real-World Dabrafenib–Trametinib Experience

Ando, T., Oya, Y., Tomiie, Y., Ogawa, K., Kuki, T., Tanabe, Y., Kato, H., Imaizumi, K., Hibi, Y., & Kawada, K. (2025). A single-center retrospective study of dabrafenib plus trametinib combination therapy in patients with BRAF V600E-positive thyroid cancer. International Journal of Clinical Oncology, 30(11), 2257–2265.
https://pmc.ncbi.nlm.nih.gov/articles/PMC12568863/
Used for: Real-world evidence showing that outcomes outside tightly controlled prospective trials can vary, particularly in heavily pretreated or clinically advanced patients. This is useful for preventing overinterpretation of the ROAR results.

22. Large European Multicentre ATC Survival Study

Jannin, A., Giudici, F., de la Fouchardière, C., Al Ghuzlan, A., Wassermann, J., Chougnet, C. N., Drui, D., Godbert, Y., Ilouz, F., Bardet, S., Zanetta, S., Roudaut, N., Batisse Lignier, M., Groussin, L., Klein, M., Zerdoud, S., Lamartina, L., Baudin, E., Decaussin-Petrucci, M., et al. (2023). Factors associated with survival in anaplastic thyroid carcinoma: A multicenter study from the ENDOCAN-TUTHYREF Network. Thyroid, 33(10), 1190–1200.
https://pubmed.ncbi.nlm.nih.gov/37855745/
Used for: Large multicentre contemporary evidence about prognosis, stage and factors associated with survival. It will help us explain why survival statistics differ substantially among stage IVA, IVB and IVC disease rather than quoting one universal ATC survival figure.

23. Liquid Biopsy and ctDNA in Thyroid Cancer

Zeyghami, W., Hansen, M. L. U., Jakobsen, K. K., Groenhøj, C., Feldt-Rasmussen, U., von Buchwald, C., & Hahn, C. H. (2023). Liquid biopsies in thyroid cancers: A systematic review and meta-analysis. Endocrine-Related Cancer, 30(12), e230002.
https://pubmed.ncbi.nlm.nih.gov/37882489/
Used for: Provides evidence on circulating tumour DNA, circulating tumour cells and other liquid-biopsy approaches in thyroid cancer. We will explicitly state that much of the BRAF diagnostic-performance evidence comes from differentiated thyroid cancer, so liquid biopsy should not be presented as a universal replacement for tumour testing in ATC.

24. Clinical Nutrition in Cancer

Muscaritoli, M., Arends, J., Bachmann, P., Baracos, V., Barthelemy, N., Bertz, H., Bozzetti, F., Hütterer, E., Isenring, E., Kaasa, S., Krznaric, Z., Laird, B., Larsson, M., Laviano, A., Mühlebach, S., Oldervoll, L., Ravasco, P., Solheim, T. S., Strasser, F., et al. (2021). ESPEN practical guideline: Clinical nutrition in cancer. Clinical Nutrition, 40(5), 2898–2913.
https://pubmed.ncbi.nlm.nih.gov/33946039/
Used for: Evidence-based nutrition screening and intervention in patients with cancer, including inadequate oral intake, loss of weight or muscle mass, nutritional counselling and escalation to enteral feeding where appropriate.

25. Herbs, Supplements and CYP-Mediated Cancer-Drug Interactions

Gougis, P., Hilmi, M., Geraud, A., Mir, O., Funck-Brentano, C., & Goldwasser, F. (2021). Potential cytochrome P450-mediated pharmacokinetic interactions between herbs, food, and dietary supplements and cancer treatments. Critical Reviews in Oncology/Hematology.
https://pubmed.ncbi.nlm.nih.gov/33930533/
Used for: Supports the need to screen herbs, foods and dietary supplements for CYP-mediated interactions with anticancer drugs. Particularly relevant because dabrafenib is involved in clinically important metabolic drug interactions.

26. Managing Interactions With Oral Anticancer Treatments

Lohr, L. K., et al. (2023). Managing drug interactions with oral anticancer treatments. Journal of the Advanced Practitioner in Oncology.
https://pubmed.ncbi.nlm.nih.gov/37576366/
Used for: Practical evidence on drug–drug, drug–food and drug–herb interactions with oral anticancer therapy. It supports pharmacist-led medication reconciliation and careful assessment before combining targeted therapy with supplements or traditional medicines.

27. ASCO Palliative-Care Guideline

Sanders, J. J., et al. (2024). Palliative care for patients with cancer: ASCO guideline update. Journal of Clinical Oncology, 42(19), 2336–2357.
https://pubmed.ncbi.nlm.nih.gov/38748941/
Used for: Supports integration of specialist palliative care with active oncology treatment for patients with advanced cancer, particularly for symptom burden, psychological distress, communication and caregiver needs.

28. ASCO–Society for Integrative Oncology Fatigue Guideline

Bower, J. E., et al. (2024). Management of fatigue in adult survivors of cancer: ASCO–Society for Integrative Oncology guideline update. Journal of Clinical Oncology, 42(20), 2456–2487.
https://pubmed.ncbi.nlm.nih.gov/38754041/ Used for: Evidence-based supportive approaches to cancer-related fatigue. It can support carefully selected integrative supportive-care discussion but does not provide evidence for treating ATC itself through Ayurveda or other complementary medicine.

29. Supportive and Survivorship Care in Advanced/Metastatic Cancer

Hart, N. H., et al. (2024). Survivorship care for people affected by advanced or metastatic cancer: MASCC-ASCO standards and practice recommendations. Journal of Oncology Practice / JCO Oncology Practice.
https://pubmed.ncbi.nlm.nih.gov/38684036/
Used for: Supports coordinated, person-centred management of quality of life, functional concerns, supportive needs, caregivers and longer-term care for people living with advanced or metastatic cancer.