BRAF Biomarker

The BRAF gene is present in all of the cells in our body and it holds the instructions for making a protein by the same name, BRAF. The normal (wild type) BRAF protein works together with a group of proteins called the EGFR/RAS/MAPK pathway to stimulate growth and division of cells in response to bodily needs and environmental cues. When the BRAF gene is mutated, it instructs an abnormal BRAF protein to continuously signal for cells to grow, and it cannot be turned off.

The National Comprehensive Cancer Network (NCCN) and American Society of Clinical Oncology (ASCO) recommend BRAF testing for everyone diagnosed with stage IV, metastatic colorectal cancer (mCRC) and before initiating therapy with anti-EGFR inhibitors.

Your doctor may also recommend re-testing the tumor for new or additional mutations when chemotherapy treatment stops working and the tumor grows again.

Knowing the details of tumor biomarkers can help you and your doctor make decisions about personalized treatment with therapies tailored specifically to the characteristics of your tumor.

• The BRAF V600E mutation is a prognostic biomarker of aggressive tumor growth. The mortality risk for patients with a BRAF mutation is more than two times higher than for those with a normal BRAF gene. Therefore, knowing about a BRAF gene mutation indicates the need for aggressive treatment.
• The BRAF mutation is also a predictive biomarker, which means it predicts that your tumor is unlikely to respond to treatment with EGFR inhibitors when given alone or in combination with chemotherapy.

Every treatment has the potential to cause some side effects. Some people may be more sensitive than others to a drug. It also depends on your other treatments, medications, vitamins, and herbal supplements. Tell your doctor or pharmacist about all the medications, vitamins, and treatments you take.

Some of the most common side effects associated with BRAF inhibitors are headache and dizziness, fatigue, diarrhea or constipation, nausea and vomiting, skin problems, joint or muscle pain, and anemia/low red blood cell levels. It is unlikely that you will experience all these side effects, but you might have some of them. Call your doctor immediately if you are experiencing severe symptoms.

For more on side effects of other chemotherapy regimens, click here.