BRCA1 and BRCA2 & Breast Cancer
Females who inherit a mutation in the BRCA1 gene, the BRCA2 gene, or both genes have an increased risk for breast cancer. Their lifetime risk of breast cancer is between 60 to 85%. They also have a 40 to 60% risk of a second breast cancer. Women without these gene mutations have a lifetime risk of just 8 to 11%.
Having a BRCA gene mutation can also affect when breast cancer occurs. Breast cancers associated with BRCA mutations often start before menopause or before age 50. This is at a much younger age compared with those who don’t have the mutated gene and who get cancer.
Having breast cancer increases the risk of getting ovarian cancer. That’s true whether or not you have a BRCA1 or BRCA2 gene mutation. Women who have had breast cancer have a lifetime risk for ovarian cancer that is three times higher than women who have not had breast cancer. Specifically, their chance is 1 in 20. Women who have never had breast cancer have a lifetime risk of ovarian cancer of 1 in 70.