BRCA Genes and Your Breast Cancer Risk

Medical Author: Melissa Stöppler, MD
Medical Editor: Barbara K. Hecht, PhD

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, up to seven times that of women who do not have BRCA gene alterations. By the age of 80, women with BRCA mutations have about an 80% chance of developing breast cancer. Having a BRCA mutation also predisposes a woman to developing breast cancer at an early age. 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 the Balkans.

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 16%-60% of women with BRCA1 or BRCA 2 mutations. Both male and female carriers of these mutant genes have a slightly increased risk for the development of other kinds of cancer, including lymphoma, colon cancer, melanoma, and pancreatic cancer.

Testing for alterations in a person's BRCA1 or BRCA2 gene is done via a blood sample. If you have a family history of breast and/or ovarian cancer, your doctor can help you decide whether BRCA testing might be appropriate for you. Women who do test positive for BRCA mutations have multiple options to decrease the likelihood of developing cancer. These options include more frequent cancer screenings, avoidance of other known risk factors, prophylactic surgery (removal of breasts or ovaries), and preventive drug therapy.