Genetic mutations in the breast cancer 1 (BRCA1) and breast cancer 2 (BRCA2) genes can increase breast cancer risk in women by age 70 years from 7% to an estimated 45%–65% and can increase ovarian cancer risk by age 70 years from 0.6% to 17%–39% (1,2). This evidence concerns the gene BRCA1 and breast cancer.