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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 55%-65% of women with a BRCA1 mutation and 45 % with a 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.

BRCA mutations also increase the risk of ovarian cancer. About 1.7% of women in the general population get ovarian cancer as compared with 40% of women with BRCA1 and 11% to 17% of women with a 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 stomach cancer, gallbladder and bile duct cancer, cervical cancer, uterine cancer, colon cancer, prostate 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.

Medically reviewed by Jay B. Zatzkin, MD; American Board of Internal Medicine with subspecialty in Medical Oncology


National Cancer Institute. BRCA1 and BRCA2: Cancer Risk and Genetic Testing.

Last Editorial Review: 11/16/2015

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