What is a BRAF genetic test?

A BRAF genetic test uses a sample of tumor tissue, bone marrow, or blood to look for changes in a gene called BRAF. Changes in your genes are also called gene variants or mutations. The test is usually done to look for changes in the BRAF gene that may be involved in cancer.

Genes are parts of DNA in your cells that you inherit from your parents. Genes carry information that controls what you look like and how your body works. The BRAF gene provides instructions for making a protein that tells your cells when to grow and divide to make new cells.

Certain changes in your BRAF gene may change the gene's instructions and lead to BRAF proteins that are too active. These abnormal BRAF proteins trigger too much cell growth. As a result, cells that have the changed BRAF gene may grow out of control and become cancer.

Changed BRAF genes and their proteins are commonly found in melanoma, the most serious form of skin cancer. Changes are also found in several other types of cancer, including colon, thyroid, ovarian, lung, and certain blood cancers.

Cancers with changes in the BRAF gene tend to grow more quickly than cancers that don't have this gene change. Knowing whether your cancer has a changed BRAF gene can help your health care provider choose the most effective treatment for you.

Changes in your BRAF genes can be acquired or inherited from your parents:

• Acquired changes in your BRAF genes develop sometime after you're born. Most changes in BRAF genes are acquired. These changes can happen if your cells make a mistake when they divide to make new cells. Changes can also happen if you're exposed to substances that cause cancer. Acquired changes in genes show up only in certain types of cells. They're usually not in sperm or egg cells, so you can't pass them down to children.
• Inherited changes in your genes are changes that you're born with. All the cells in your body have the gene change, including your egg or sperm cells. That means you can pass the change down to your children. Inherited changes in the BRAF gene are very rare, but they can increase your risk of cancer or cause different types of genetic conditions that are present from birth.

Other names: BRAF gene mutation analysis, Melanoma, BRAF V600 mutation

What is it used for?

BRAF genetic testing may be used to:

• Look for changes in the BRAF gene in certain types of cancer. This information may be used to diagnose certain types of cancer and/or guide treatment decisions.
• Check for inherited changes in the BRAF gene. This is not a routine screening test. But it may be used if your personal or family health history suggests that you may have a high risk for cancer or another condition that's caused by inherited changes in the BRAF gene. Your risk of cancer from inherited gene change may be high if:
  • You or a family member have had cancer at an unusually young age
  • You have several close family members who have the same type of cancer
  • You or a family member have two or more types of cancer

Why do I need a BRAF genetic test

You may need a BRAF genetic test if you:

• Have a cancer that could be caused by changes in your BRAF gene. The results from a BRAF genetic test can help your provider:
  • Predict how fast your cancer may grow.
  • Know whether targeted treatment is likely to help you. Targeted treatment for cancer with changes in BRAF genes blocks or slows the abnormal proteins that make cancer grow. These medicines could be harmful if they are prescribed for cancers that don't have changed BRAF genes. So BRAF testing is needed to match you with the best treatment for your cancer.
  • Understand how your cancer may respond to treatments, such as chemotherapy or radiation therapy.
• Have a personal or family health history that increases your risk of cancer involving inherited changes in your BRAF gene. A BRAF genetic test can help you estimate and manage your cancer risk. The test can also show whether you could pass a changed BRAF gene to your children.
• Have a family health history of a genetic condition caused by BRAF gene changes. BRAF genetic testing can help you understand if you and your partner have BRAF gene changes that you could pass to your children.

If you're considering a BRAF gene test to look for an inherited gene change, a genetic counselor can help you consider the pros and cons of this test.

What happens during a BRAF genetic test?

If you're having a BRAF genetic test because you have cancer, the test will depend what type of cancer you have:

• For solid tumors, the test often uses a sample of cells from the tumor. The sample may be taken:
  • During surgery to remove the entire tumor.
  • With a biopsy to remove a small amount of tissue. The type of biopsy you have depends on where your cancer is located. A biopsy may be done with:
    • A hollow needle inserted through your skin. Imaging tests, such as ultrasound may be used to guide the needle.
    • Minor surgery to remove a sample of tissue (an incisional biopsy).
  • With a blood test. If surgery or a biopsy isn't possible, you may have a blood test to look for DNA that the tumor has shed in your bloodstream. This is called a "liquid biopsy." To do a blood test, a health care professional will use a small needle to take a blood sample from a vein in your arm.
• For blood cancer, a blood test or a bone marrow test may be used. Marrow is soft, spongy tissue found inside of bones. Most bone marrow samples are taken from the back of the hip bone.

If you're having a BRAF genetic test to check for inherited gene changes, you will usually have a blood test.

Will I need to do anything to prepare for the test?

If you're having a blood test, you usually don't need any special preparations. Ask your provider about how to prepare for other types of BRAF gene tests.

Are there any risks to the test?

The risks of a BRAF gene test depend on how your sample is collected. Talk with your provider about your risks.

In general, with a biopsy, you may have soreness, pain, or bleeding where the tissue was removed.

A blood test has very little risk. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

After a bone marrow test, you may feel stiff or sore where the sample was taken. This usually goes away in a few days. Serious symptoms are very rare, but may include swelling, bleeding at the site, or fever.

What do the results mean?

If you have cancer and your test results show:

• You have a change in your BRAF gene, your provider may prescribe medicines that are designed to target the changed BRAF proteins that are making your cancer grow. You may also need other treatments.
• You don't have a change in your BRAF gene, your provider will prescribe another type of treatment for your cancer.

If you don't have cancer and your results show you have a change in your BRAF gene, it does not mean you'll get cancer. But, depending on the change, you may have a higher risk of developing cancer.

You may be able to reduce your risk by having more frequent cancer screenings. For example, to reduce or risk of melanoma, you can have more skin exams to check your whole body for moles and other suspicious growths. Cancer screening can help catch cancer early when it's easier to treat.

If you have an inherited change in your BRAF gene, talk with your provider or a genetic counselor to learn about the risks of passing the change to your children.

Learn more about laboratory tests, reference ranges, and understanding results.