Genetics and the management of women at high risk for breast cancer.

It is estimated that 5%-10% of all breast cancers in women are associated with hereditary susceptibility due to mutations in autosomal dominant genes, such as BRCA1 and BRCA2, p53, pTEN, and STK11/LKB1. Another 15%-20% of female breast cancers occur in women with a family history but without an apparent autosomal dominant inheritance pattern, and are probably due to other genetic factors with environmental influence. Approximately 7%-10% of ovarian cancers occur in women with hereditary susceptibility, primarily secondary to mutations in BRCA1 and BRCA2, with smaller contributions from mutations in mismatch repair genes associated with the hereditary nonpolyposis colorectal cancer and other, as yet undiscovered, genes.