Genetic Risk Assessment and BRCA Mutation Testing for Breast and Ovarian Cancer Susceptibility

This USPSTF recommendation was first published in Ann Intern Med. 2005;143:355-361. http://www.ahrq.gov/clinic/uspstf05/brcagen/brcagenrs.htm.

Clinical Considerations

• These recommendations apply to women who have not received a diagnosis of breast or ovarian cancer. They do not apply to women with a family history of breast or ovarian cancer that includes a relative with a known deleterious mutation in BRCA1 or BRCA2 genes; these women should be referred for genetic counseling. These recommendations do not apply to men.
• Although there currently are no standardized referral criteria, women with an increased-risk family history should be considered for genetic counseling to further evaluate their potential risks.
• Certain specific family history patterns are associated with an increased risk for deleterious mutations in the BRCA1 or BRCA2 gene. Both maternal and paternal family histories are important. For non-Ashkenazi Jewish women, these patterns include 2 first-degree relatives with breast cancer, 1 of whom received the diagnosis at age 50 years or younger; a combination of 3 or more first- or second-degree relatives with breast cancer regardless of age at diagnosis; a combination of both breast and ovarian cancer among first- and second-degree relatives; a first-degree relative with bilateral breast cancer; a combination of 2 or more first- or second-degree relatives with ovarian cancer regardless of age at diagnosis; a first- or second-degree relative with both breast and ovarian cancer at any age; and a history of breast cancer in a male relative.
• For women of Ashkenazi Jewish heritage, an increased-risk family history includes any first-degree relative (or 2 second-degree relatives on the same side of the family) with breast or ovarian cancer.
• About 2 percent of adult women in the general population have an increased-risk family history as defined here. Women with none of these family history patterns have a low probability of having a deleterious mutation in BRCA1 or BRCA2 genes.
• Computational tools are available to predict the risk for clinically important BRCA mutations (that is, BRCA mutations associated with the presence of breast cancer, ovarian cancer, or both), but these tools have not been verified in the general population. There is no empirical evidence concerning the level of risk for a BRCA mutation that merits referral for genetic counseling.
• Not all women with a potentially deleterious BRCA mutation will develop breast or ovarian cancer. In a woman who has a clinically important BRCA mutation, the probability of developing breast or ovarian cancer by age 70 years is estimated to be 35 percent to 84 percent for breast cancer and 10 percent to 50 percent for ovarian cancer.
• Appropriate genetic counseling helps women make informed decisions, can improve their knowledge and perception of absolute risk for breast and ovarian cancer, and can often reduce anxiety. Genetic counseling includes elements of counseling; risk assessment; pedigree analysis; and, in some cases, recommendations for testing for BRCA mutations in affected family members, the presenting patient, or both. It is best delivered by a suitably trained health care provider.
• A BRCA test is typically ordered by a physician. When done in concert with genetic counseling, the test assures the linkage of testing with appropriate management decisions. Genetic testing may lead to potential adverse ethical, legal, and social consequences, such as insurance and employment discrimination; these issues should be discussed in the context of genetic counseling and evaluation for testing.
• Among women with BRCA1 or BRCA2 mutations, prophylactic mastectomy or oophorectomy decreases the incidence of breast and ovarian cancer; there is inadequate evidence for mortality benefits. Chemoprevention with selective estrogen receptor modulators may decrease incidence of estrogen receptor-positive breast cancer; however, it is also associated with adverse effects, such as pulmonary embolism, deep venous thrombosis, and endometrial cancer. Most breast cancer associated with BRCA1 mutations is estrogen receptornegative and thus is not prevented by tamoxifen. Intensive screening with mammography has poor sensitivity, and there is no evidence of benefit of intensive screening for women with BRCA1 or BRCA2 gene mutations. Magnetic resonance imaging (MRI) may detect more cases of cancer, but the effect on mortality is not clear.
• Women with an increased-risk family history are at risk not only for deleterious BRCA1 or BRCA2 mutations but potentially for other unknown mutations as well. Women with an increased-risk family history who have negative results on tests for BRCA1 and BRCA2 mutations may also benefit from surgical prophylaxis.