In the 1990s, mutations in two genes, BRCA1 (BReast CAncer 1) and BRCA2 (BReast CAncer 2), were shown to be involved in inherited breast cancer. It is estimated that 40 percent to 90 percent of families with an inherited form of breast cancer have a defective copy of the BRCA1 or BRCA2 gene.

BRCA1 and BRCA2 are called "tumor suppressor genes" because they make proteins that help prevent the cells from forming tumors. If one of these genes is changed through a mutation, the protein may not do its job, making it easier for a tumor to develop. Women who inherit a mutated copy of either the BRCA1 or BRCA2 gene have an increased chance of developing breast cancer. In addition, there may be an increased risk for other cancers.

* Note: These risks are based on current research and may change over time.

Carriers of a BRCA1 mutation have up to a 60% risk of ovarian cancer by age 70. The risk of ovarian cancer is slightly lower for BRCA2 carriers — about 30% by age 70. Men with a BRCA1 mutation have about three time the risk of prostate cancer when compared to men with normal BRCA1 genes. BRCA2 mutations may also increase prostate cancer risk.

Does everyone with an altered BRCA1 or BRCA2 gene develop cancer?

No, not all women who inherit a mutated BRCA1 or BRCA2 gene will develop cancer. Among every 100 women with an altered BRCA1 or BRCA2 gene, 50 to 85 of them will develop breast cancer, compared with about 12 of every 100 women who do not have the altered gene.

It is not always clear why some women with BRCA1/BRCA2 mutations develop cancer and others do not. Some women choose to have breast and tissue surgically removed as a preventive measure. This decreases, but does not eliminate, the risk of developing cancer.

Should You Be Tested?

You are most likely to be at risk for inherited breast cancer if you have a family history of this disease or ovarian cancer. Meeting with a genetic counselor or a doctor trained in genetics will help you decide if genetic testing is right for you.

Why does a genetic counselor need my medical records?

Medical records can be very helpful to your genetic counselor or doctor. Medical records of family members who have had breast cancer at younger ages are particularly helpful. The family member who had cancer (or his/her next of kin) will need to sign a medical record consent form from the hospital where he or she was treated to get the records released to you. Sometimes medical records are not available on family members who died a long time ago, but it may be possible to get a death certificate from the town or state where they lived.

Aetna Member: If you would like more information about breast cancer and breast cancer prevention, please call (888) 322-8742.
Miembros de Aetna: Si desean mayor información sobre el cáncer de seno y sobre su prevención por favor llame al (888) 322-8742.