BRCA Genes and Your Breast Cancer Risk

Medical Author: Melissa Stöppler, MD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR

BRCA, known as the "breast cancer gene," is one of several genetic mutations (alterations in the body's genetic material) that have been associated with the development of breast and ovarian cancer. Changes in two genes, known as BRCA1 and BRCA2 (short for breast cancer 1 and breast cancer 2), can be inherited and lead to a markedly increased risk for developing breast cancer and ovarian cancer.

Only about 5% of women with breast cancer are found to carry a mutated BRCA gene. Studies have confirmed that women who carry these BRCA mutations have a high risk for development of breast cancer, about five times that of women who do not have BRCA gene alterations. Overall, around 12% of all women will get breast cancer during their lifetime; in contrast, around 60% of women with a BRCA1 or BRCA2 mutation will get the disease. Having a BRCA mutation also predisposes a woman to developing breast cancer at an early age (before menopause). The incidence of BRCA mutation is higher in some ethnic groups, such as people of Ashkenazi (European) Jewish origin and in some populations in Iceland, the Netherlands, and Norway.

Men who carry one of the BRCA mutations also have an increased risk for breast cancer.

BRCA mutations also increase the risk of ovarian cancer. About 1.7% of women in the general population get ovarian cancer as compared with 15% to 40% of women with BRCA1 or BRCA 2 mutations....