Hereditary Breast Cancer Risk

Each year, about 200,000 people in the U.S. are diagnosed with breast cancer. Most do not have an increased inherited risk for the disease. Age, diet and many other lifestyle and environmental factors more often influence an individual’s risk of developing breast cancer. Although we’re hearing more about hereditary causes of breast cancer-because we’re learning more about genetics and we’re developing better screening procedures-only 5-10% of all breast cancers are related to known inherited factors.

“Breast cancer” genes

Cancer is caused by genetic abnormalities or mutations. Some breast cancers are caused a mutation in either or both of the so-called breast cancer genes: BReast CAncer 1 and 2 (BRCA1/BRCA2). All of us, both men and women, have two copies of these genes-one from our mother and one from our father. If either parent has a BRCA mutation, it can be inherited by their children.

Having a BRCA (pronounced “bra-cah”) mutation doesn’t guarantee someone will develop breast cancer, but it increases their lifetime risk to 80%, compared to 12% in the general population. BRCA carriers are more likely to develop the disease before menopause and in both breasts, and are also at increased risk for ovarian cancer.

Genetic counseling and testing

Based on your individual and family medical history, a specially-trained genetic counselor can help you understand your risk for developing breast cancer and determine whether you are a candidate for genetic testing. If you are tested, she can help interpret the results.

Testing for a BRCA mutation is recommended only for individuals who have a significant personal or family history of breast cancer. Your chances of having a BRCA1 and/or BRCA2 mutation are greater if:

• Your mother, sister or daughter has/had breast cancer.
• You have/had breast cancer in one breast before age 45 or both breasts at any age.
• You or a family member has/had both breast and ovarian cancer.
• You are of Ashkenazi Jewish descent.
• A male relative has/had breast cancer.

Genetic testing for a BRCA mutation involves a simple blood test. Current BRCA tests cannot identify other unknown genetic mutations that may increase your chance of developing breast cancer.

Insurance often covers the cost of genetic testing if the individual has a strong family history of cancer. The Health Insurance Portability and Accountability Act (HIPAA) prohibits insurance carriers from releasing your genetic testing results to anyonewithout your written permission. Your genetic counselor can tell you more about privacy laws regarding genetic testing.