Study Assesses Frequency of BRCA Mutations Among Women with Triple-Negative Breast Cancer
Date of publication: August 22, 2013
Rates of BRCA gene mutations tend to be high among women with triple-negative breast cancer who are referred for genetic testing, particularly among women who were diagnosed with breast cancer at a younger age. These results were published in Annals of Surgical Oncology.
Inherited mutations in two genes-BRCA1 and BRCA2-have been found to greatly increase the lifetime risk of developing breast and ovarian cancer. Mutations in these genes can be passed down through either the mother's or the father's side of the family.
Genetic testing for BRCA mutations may be recommended for people who have an increased likelihood of a mutation based on their own or their family's cancer history. For women who have already been diagnosed with breast cancer, genetic testing provides information about the risk of additional breast or ovarian cancers. If a BRCA mutation is identified, options to manage risk include complete removal of both breasts and/or ovaries before another cancer develops, or more intensive screening in an effort to detect a new cancer at an early stage.
To evaluate the frequency of BRCA1 and BRCA2 mutations among women with triple-negative breast cancer, researchers conducted a study among 469 women with triple-negative breast cancer who had been referred for genetic counseling. A total of 450 of the women had evaluable test results.
These results provide additional evidence that women with triple-negative breast cancer-particularly those diagnosed at a young age-have higher-than-average rates of BRCA mutations. Rates of BRCA mutations are also high among women with triple-negative breast cancer who are of Ashkenazi Jewish descent.
- 31% of the women had a BRCA1 or BRCA2 mutation. BRCA1 mutations were detected in 106 of the women and BRCA2 mutations were detected in 32 of the women.
- BRCA mutations were more common in women who were diagnosed with triple-negative breast cancer at a young age: mutations were found in 44% of women diagnosed before the age of 40, 27% of women diagnosed during their 40s, 25% of women diagnosed during their 50s, 13% of women diagnosed during their 60s, and 17% of women diagnosed at age 70 or older.
- The prevalence of BRCA mutations also varied by race and ethnicity. Mutations were detected in 20% of African-American women, 50% of women of Ashkenazi Jewish descent, 29% of Asian women, 33% of white women, and 20% of Hispanic women.
In the United States, the National Comprehensive Cancer Network (NCCN) recommends genetic risk assessment, counseling, and management for women diagnosed with triple-negative breast cancer at age 60 or younger. Women with other personal or familial characteristics suggestive of a BRCA1 or BRCA2 mutation may also be candidates for testing. Decisions about genetic testing are complex, and genetic counseling provides individualized information about the need for testing and the implications of testing.
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