How does a BRCA mutation increase cancer risk?
Normally, the BRCA1 and BRCA2 genes are tumor suppressors. They help prevent cancer by controlling cell growth. But if either of these genes has mutations, it may no longer work properly. Cells may grow abnormally and form tumors. The risk of getting breast cancer is much higher than normal for women with a BRCA mutation. BRCA mutations also raise the risk for ovarian cancer. • An average woman in the U.S. has about a 12 percent chance of getting breast cancer if she lives to the age of 90. Her lifetime risk of getting ovarian cancer is about 1.4 percent. • A woman with a BRCA mutation has about a 60 percent chance of getting breast cancer by age 70. She also has a 15 percent to 40 percent chance of getting ovarian cancer in her lifetime. Men with BRCA mutations are also at higher risk for breast cancer. They may be at increased risk for pancreatic and prostate cancers, too. Male breast cancer is rare: Less than 1 percent of all breast cancer cases occur in men. But a man who does have