They found that 3.5 percent of Hispanic women entered in a Northern California breast cancer registry had the BRCA1 genetic mutation, compared to 8.3 percent of Ashkenazic Jews and 2.2 percent of non-Ashkenazic white women.
The BRCA1 gene mutation raises the risk of breast and ovarian cancer, with the risk of developing breast cancer by age 70 put at 65 percent, the researchers said. Women who find out they have the mutation are advised to be vigilant, and some opt for preventive chemotherapy or surgery.
The study, published in the Journal of the American Medical Association, looked at more than 3,000 cancer patients in the United States diagnosed before age 65 between 1996 and 2005.
The lowest incidence of the mutation was found among Asian-American women at 0.5 percent, and it was found among 1.3 percent of black women patients.
However the BRCA1 mutation was most common among black women diagnosed with the disease before age 35—16.7 percent, the researchers found.
In an accompanying editorial, two University of Chicago researchers said the findings spotlighted that minorities are rarely tested for the BRCA1 gene. They cited data showing that only 10 percent of BRCA1 testing procedures are done on U.S. minority populations.