Gene mutations common in black women at high risk for breast cancer
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CHICAGO — More than one-fifth of black women with breast cancer who were characterized as being at higher risk for the disease carried an inherited abnormality in at least one of 18 genes associated with breast cancer susceptibility, according to results of a single-center study presented at the ASCO Annual Meeting.
The mutations were more common among women with aggressivetriple-negative breast cancer (TNBC), early-onset disease, and a family history of breast and ovarian cancers. Those findings suggest broader genetic screening could benefit these patients and their families, researchers said.
“The incidence of advanced breast cancer is increasing among young women, particularly African-American women, who would not yet have reached the age of breast cancer screening and therefore not had the opportunity to have their breast cancers detected early,” said Jane E. Churpek, MD, assistant professor of medicine at the University of Chicago. “African-American women are disproportionately affected by early-onset breast cancer and develop more aggressive forms of breast cancer, such as triple-negative breast cancer, compared with women of other racial and ethnic backgrounds. This trend makes it even more crucial that we understand exactly who is at risk.”
Churpek and colleagues conducted the study to evaluate whether inherited variations in genes linked to breast cancer contributed to this disparity among black women.
The analysis included 249 black women with breast cancer who were referred for genetic counseling at The University of Chicago. The researchers used targeted genomic capture and next-generation sequencing to screen DNA for mutations in 18 breast cancer susceptibility genes.
According to study results, 56 patients (22%) were found to carry at least one loss-of-function mutation. The mutations were found in the BRCA1 (n=26), BRCA2 (n=20), CHEK2 (n=3), PALB2 (n=3), ATM (n=5) and PTEN (n=1) genes.
Damaging mutations were most frequent among patients with TNBC (30%), patients diagnosed before aged 45 years (27%), patients with a second primary cancer in the breast (49%), and patients with a family history of either breast or ovarian cancer in a close relative (30%).
“For many years, we’ve seen breast cancer take a heavy toll on African-American women, and this study begins to resolve unanswered questions about what’s driving these disparities,” Churpek said. “While larger studies are needed to confirm our results and compare them to other populations, we hope our findings will lead to increased awareness about potentially life-saving genetic screening for African-American women with a personal or family history of early onset or aggressive forms of breast cancer, and their relatives.”
For more information:
Churpek JE. Abstract #CRA1501. Presented at: ASCO Annual Meeting; May 31-June 4, 2013; Chicago.
Disclosure: The researchers report no relevant financial disclosures.