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Bonnie Beaver's OB/GYN suggested she consider genetic testing to see if she was at a high risk for breast cancer after her sister was diagnosed with it at age 29. "I said, 'Why would I ever want to know if I had a better chance of getting cancer?'" says Bonnie, of Brooklyn Park, MN, "I did not want to know."
Two years ago, a lump in Bonnie's breast turned out to be cancerous. Again, genetic testing was suggested. If Bonnie was positive for a genetic mutation on the breast cancer genes BRCA1 or BRCA2, the chances of the cancer returning would be high, and that would determine the course of her treatment.
Bonnie's BRCA test came back positive, increasing the odds that her cancer would return either in the tissue left behind after a lumpectomy or in the other breast. So instead of the more conservative surgery she would likely have opted for without testing, she opted for a double mastectomy, which gives her increased protection against future cancer. Because BRCA mutations also increase ovarian cancer risk, the mom of four also recently had her ovaries removed. Both procedures have helped ease her worries about future cancers. "I can finally put that chapter behind me," she says.
What Is BRCA Testing?
BRCA-related cancers usually involve both breasts, include a family history of breast and/or ovarian cancer and are more likely to occur at a younger age. A blood test to look for mutations, or errors, on the BRCA1 or BRCA2 genes can determine whether a woman is at higher-than-average risk for breast cancer. Testing is usually recommended for two groups of people:
- Breast cancer patients who have a strong family history of the disease, or who are younger than 50 and have been adopted or have no sisters or aunts. Finding out whether they are BRCA-positive can help them manage their risk for other cancers, such as ovarian, or a new breast cancer as they have a high probability of multiple cancers over their lifetime.
- Family members of people who are BRCA positive. Knowing whether you carry the gene mutation can help you prevent or detect cancer earlier down the road, either through regular cancer screenings or preventive measures such as mastectomy or medications.
Knowing whether you are BRCA positive also helps both groups to reduce their risk of ovarian cancer, which is also more common in BRCA carriers.
If you are BRCA-positive, it does not mean you will definitely get cancer, but it does mean that your risk of breast and ovarian cancers are greater than that of someone without the mutations--up to 84 percent more for breast cancer and 50 percent for ovarian cancer. "About 10 percent of breast cancers are inherited, and of those about half are due to a gene change in BRCA1 or BRCA2," says Kathy Helzlsouer, M.D., director of the Prevention and Research Center at Mercy Medical Center in Baltimore, MD. "The other half of suspected inherited types of cancer are not currently explained."
BRCA testing is only recommended for people with a strong family history of breast cancer, which comprises about 2 percent of American women. (Before testing, these women should seek genetic counseling).This includes women with:
- two first-degree relatives (mother, sister) with breast cancer, one of whom was younger than 50 at the time
- three or more first- or second-degree relatives (aunt, grandmother) with breast cancer, regardless of age
- a first-degree relative with cancer in both breasts
- a history of breast cancer in any male relative
Women of Ashkenazi Jewish descent also have a high incidence of BRCA mutations and should be tested if there is any family history of breast or ovarian cancer.
