BRAF Mutation

April 29, 2026

This page was reviewed under our medical and editorial policy by Matthew Lee, M.D., M.P.H., Medical Oncologist and Assistant Professor of Medical Oncology, City of Hope^® Cancer Center Duarte.

The BRAF gene (B-Raf proto-oncogene, serine/threonine kinase) provides instructions to a protein responsible for managing cell growth and division. When a mutation occurs in this gene, it may lead to tumor development.

What Is a BRAF Mutation?

Found on chromosome 7, the BRAF gene is classified as an oncogene. In healthy people, oncogenes switch on and off as needed. When the BRAF gene spontaneously mutates, the gene no longer turns on and off correctly. Instead, the switch is stuck in the “on” position, signaling cells to keep dividing without stopping. This uncontrollable cell growth can cause cancer.

Types of BRAF gene mutations

Researchers have discovered more than 30 different types of BRAF gene mutations. The most common is V600E.

BRAF V600E and BRAF V600K: With melanoma, BRAF V600E and BRAF V600K comprise about 90% of BRAF mutations.

Non-V600 BRAF: Around 50% to 80% and 22% to 30% of BRAF mutations are non-V600 mutations with non-small cell lung cancer (NSCLC) and colorectal cancer, respectively.

Acquired versus inherited BRAF genes

Most changes in BRAF genes are acquired and aren’t passed on from parent to child.

However, very rarely, BRAF mutations can be passed on from parent to child. These inherited mutations can increase the risk of cancer or cause various types of genetic conditions that are present from birth.

BRAF Gene Mutation and Cancer

BRAF mutations are present in roughly half of all melanoma cases — a discovery that has unlocked new treatments for patients with metastatic or locally advanced melanoma (stage IIIB or stage IIIC).

Though BRAF gene mutations are most commonly found in melanoma, the most dangerous form of skin cancer, they’re associated with several cancers, including:

• Non-small cell lung cancer (NSCLC) or lung adenocarcinoma, which occurs more commonly in smokers or former smokers but can also still occur in never-smokers, women and young patients
• Colorectal cancer, particularly in women and people diagnosed at an older age, without a family history and with right-sided colon cancer
• Thyroid cancer, especially anaplastic thyroid cancers (very aggressive) and papillary thyroid cancers
• Serous ovarian cancer
• Certain blood cancers, including hairy cell leukemia and non-Hodgkin lymphoma
• Certain brain cancers, including glioblastoma, pilocytic astrocytoma and pediatric low-grade glioma

Importantly, cancers with BRAF gene changes — either alone or in combination with additional mutations — tend to grow more quickly than they would otherwise.

Key takeaway: The presence or absence of BRAF mutations can significantly influence treatment planning and the selection of optimal therapies, including targeted therapies.

BRAF Testing

The care team may recommend BRAF genetic testing, a process that analyzes the tumor’s DNA to see if a BRAF mutation is present.

The results are important to understanding:

• The patient’s risk of cancer
• How fast the cancer may grow
• Whether the patient is a candidate for targeted treatment
• How the cancer may respond to treatments, such as chemotherapy or radiation therapy
• Whether the patient could pass a mutated BRAF gene to his or her children

A BRAF genetic test may be considered if the patient:

• Has a cancer that could be caused by BRAF gene mutations
• Has a personal or family health history that raises the patient’s risk of cancer involving inherited BRAF gene mutations
• Has a family health history of a genetic condition caused by BRAF gene mutations

The Testing Process

The care team doctor will biopsy the tumor and send the tissue sample to a lab for genetic testing, normally through comprehensive next-generation sequencing (NGS). The results will show if the sample is positive or negative for the BRAF mutation, as well as the specific mutation type.

If a biopsy isn’t possible because of tumor location or other factors, the care team may recommend a blood test with circulating tumor DNA (ctDNA), which provides a quicker examination of the genomic profile of the cancer but is dependent on whether tumor cells are examined in the blood sample.

BRAF Inhibitors

BRAF inhibitors are targeted therapies that help slow the growth of cancer cells with BRAF gene mutations. Instead of killing cancer cells like traditional chemotherapy, these drugs work by blocking the signals that tell the cancer to grow and spread.

Combination Therapy

BRAF inhibitors are primarily often used in combination with drugs that block the growth of a tumor at other points in the signaling pathway, for example, MEK inhibitors. Notably, taking a MEK inhibitor along with a BRAF inhibitor can lead to fewer side effects than using a BRAF inhibitor alone. The combination also tends to work for a longer time period.

For example:

• Using a combination of a BRAF inhibitor and a MEK inhibitor has been a game changer for many metastatic melanoma patients — helping to slow the cancer and improve outcomes.
• Combining BRAF inhibitor dabrafenib and MEK inhibitor trametinib is also approved for treating non-small cell lung cancer with a BRAF V600E mutation. In studies, about 64% of patients responded to this treatment.

The following BRAF inhibitors are approved for use on certain tumors by the U.S. Food and Drug Administration (FDA):

• Vemurafenib, approved for BRAF V600E mutations
• Dabrafenib, approved (in combination with trametinib) for both BRAF V600 E and V600K mutations
• Encorafenib, approved (in combination with binimetinib) for both BRAF V600E and V600K mutations

In some cases, immune checkpoint inhibitors work by helping the immune system recognize and attack cancer cells. In simple terms, they “take the brakes off” the immune system, allowing it to better fight the cancer.

BRAF Inhibitor Side Effects

Understanding the benefits and risks of taking BRAF inhibitors is important.

Possible side effects include:

• Skin thickening
• Itching
• Rash
• Headache
• Sun sensitivity
• Joint pain
• Fever
• Hair loss
• Fatigue
• Nausea

More serious side effects include:

• Heart rhythm issues
• Kidney failure
• Liver problems
• Severe allergic reaction
• Serious eye or skin problems
• Increased blood sugar levels
• Bleeding

Routine monitoring helps manage side effects by giving doctors the information — when and where they need it — to safely change the dosage.

BRAF Test Results

Testing positive for a BRAF gene mutation helps the care team make more informed decisions about the patient’s care, including:

• Choosing the most effective medicines to target cancer cells.
• Understanding how quickly the tumor may grow or how large it may get
• Predicting how the cancer may respond to treatments like chemotherapy or radiation therapy

It’s just as important to know if the patient doesn’t have a BRAF gene mutation. Using treatments that target BRAF mutations on tumors that don’t have them may actually lead to tumor progression. That’s why testing is such an important step in personalizing cancer treatment.

If a patient has cancer and his or her test shows a BRAF gene mutation, the care team may recommend targeted therapies or immunotherapy regimens. Depending on the patient’s individual needs, he or she may also need other treatments.

If the patient doesn’t have cancer, but his or her test shows a BRAF gene change, it doesn’t mean he or she will necessarily get cancer. But certain types of BRAF changes may increase risk.

The good news is patients can take steps to lower risk — and getting regular or additional cancer screenings is a meaningful start. For example, if a BRAF mutation increases a patient’s risk for developing melanoma, the care team may suggest regular full-body skin checks to catch any unusual spots early.