BRCA 1 and BRCA 2 are tumor suppressor genes that help protect against cancer. It is known that when a patient has an altered form of the gene (a mutation) she has a higher likelihood of developing cancer. Mutations in the BRCA 1&2 genes are associated with an increased risk of breast, ovarian, and other cancers.
It is important to note that only 5% of breast cancers are associated with BRCA gene mutations, but the more members in a family with breast and/or ovarian cancer, the greater the chance that there is an associated BRCA gene mutation. This is especially true when the number of involved family members exceeds three. It is estimated that only 1/400 – 1/1,000 people in the general population has this abnormal gene, yet the incidence is much higher in certain ethnic groups. Among Ashkenazi (Central and Eastern European) Jews, the incidence is as high as 1/40.
The incidence of breast cancer in patients with these mutations can range from 50-85%, and ovarian cancer incidence can range from 10 to 40%. Patients are more likely to carry a BRCA mutation if they have had early onset breast or ovarian cancer, have a family member with early breast or ovarian cancer, have a male family member with breast cancer, or have several family members with either of these cancers.
Genetic testing can be very expensive, though most insurance companies do cover the cost of testing if the patient is diagnosed to be at increased risk for hereditary cancer. We, therefore, refer our patients to a qualified genetic counselor, who gathers the patient’s medical and family history and evaluates risk using updated models that predict the likelihood of a BRCA gene mutation. Having an early diagnosis of cancer (prior to age 50) and/or a strong family history of cancer increases the likelihood of insurance coverage.
If a patient tests positive for a BRCA gene mutation, her children have a 50% chance of having the gene mutation as well. If the patient’s children test positive, steps can then be taken to reduce cancer risk. These include earlier and more frequent screening, consideration of preventive surgeries, and taking medications such as Tamoxifen to reduce cancer risk. For any person found to carry a BRCA mutation, the following information should be discussed with a qualified genetics professional.
- Birth control pill use can lower the risk of developing ovarian cancer
- Close monitoring of the ovaries with clinical exams and ultrasound every 6 months should be considered
- The risks and benefits of removing ovaries and tubes once childbearing is complete
- Use of certain chemo-protective agents like Tamoxifen and Raloxifene before cancer occurs – these are very effective in reducing the incidence of breast cancer in patients with BRCA mutations
- Annual monitoring of breasts with mammography and breast MRI should begin at age 25
- Some women, especially those with a prior breast cancer, may want to consider surgical removal of the breasts.