How does a BRCA1 or BRCA2 gene mutation affect my risk of cancer?


If you have a defect (mutation) in the BRCA1 or BRCA2 gene, it means that you may have an 18 to 62 percent chance of getting ovarian cancer.

Everyone has the BRCA genes. They are designed to help prevent the overproduction of cells. Only about 10 percent of women with ovarian cancer have a mutation in one or both of these genes.

If you have a history of ovarian cancer in your family, you can seek the help of a qualified genetic counselor to conduct an extensive genetic/medical history and obtain advice about whether or not to proceed with the test. If either of these genes is defective, it doesn't mean you'll get cancer. Plus, you can take preventive steps such as having your ovaries removed to significantly reduce your risk. Seek advice from your healthcare professional on how to proceed.

Rae Wruble, RN
Nursing Specialist

Research indicates that women who carry a harmful BRCA1 or BRCA2 gene mutation have up to a 70 to 80 percent risk of developing breast cancer, and up to a 25 to 50 percent risk of developing ovarian cancer. Preventive breast surgery can drop the breast cancer risk 90 percent, and preventive ovarian surgery can drop the ovarian cancer risk 96 percent.

Men who test “positive” for a harmful BRCA1 or BRCA2 mutation, have a higher risk of developing breast or prostate cancer. Knowing that you have a harmful BRCA mutation can be lifesaving for you and your family.

Doctors caution that testing positive for the BRCA gene is not a guarantee that you will develop breast cancer. Your risk of developing the disease is higher, but many women won’t get the cancer.

In general, about 1 in 8 women will get breast cancer sometime during their lives, according to the National Cancer Institute. Having the BRCA1 or BRCA2 mutation increases your risk of the disease. According to the strongest scientific data:

  • About 1 in 10 cancers are passed down through families.
  • Breast cancer develops in 72 percent of women with the BRCA1 mutation.
  • About 69 percent of women who inherit a BRCA2 mutation will develop breast cancer.

If you have a BRCA mutation, talk to your doctor about your risk factors, screening recommendations and prevention options.

Dr. David A. Fishman, MD
Gynecologic Oncologist

Women who carry a breast cancer gene 1 (BRCA1) or breast cancer gene 2 (BRCA2) gene mutation have a 56 to 85 percent chance of developing breast cancer by age 70. The associated lifetime risk for ovarian cancer is 20 to 40 percent for BRCA1 mutations and 10 to 27 percent for BRCA2 mutations.

In addition, BRCA2 mutations are associated with an increased risk of male breast cancer, and mutations in both genes may slightly increase the risk of prostate and colon cancer. Research continues to define the cancer spectrum associated with BRCA1 and BRCA2 mutations, and the magnitude of risk for each type of cancer.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.