Mutation Testing for Colorectal Cancer

Cathy Eng, professor and director, Department of Gastrointestinal Medical Oncology, University of Texas MD Anderson Cancer Center, says mutation testing is done to determine which, if any, therapies could be used in addition to chemotherapy.

KRAS mutations are very common — occurring in about 30 to 50 percent of patients — and can help a physician steer away from certain expensive drugs.

BRAF mutations are not common and occur in about 5 to 8 percent of patients. A BRAF mutation signifies to a physician that a patient must be treated aggressively upfront.

Unfortunately, Eng says, not all mutations can be targeted with a specific drug.