BRCA1: Startling New Findings Point to Need for Wider Testing

If you’ve had breast cancer, you’ve no doubt heard about BRCA1 and BRCA2 testing, often offered as an option to women with a strong family history of breast cancer, especially those who’ve been diagnosed early (under age 35), and Ashkenazi Jewish women. Now, it appears that the testing net should be cast much wider.

BRCA1 and BRCA2 are genes that manufacture proteins that help DNA repair itself. When those genes mutate and no longer manufacture the protein, DNA tends to become damaged, which leads to mutations, which can lead to cancer. Mutations in either of the BRCA (BReast CAncer) genes are inherited; thus identifying a mother or grandmother, sister or aunt with a BRCA gene mutation points to others in her family having the same mutation. And being more likely to develop breast cancer. In the case of Ashkenazi Jewish women, much more likely: these women have a 65% chance of developing breast cancer by age 70, as compared to 12% in women without the mutated gene. In addition, those with BRCA issues are more likely to develop ovarian cancer.

Results of a study published Dec. 26 in the Journal of the American Medical Association show that Hispanic women, like Ashkenazi Jewish women, are also more likely to experience BRCA1 issues. A large multiracial study involving over 3,000 San Francisco-area breast cancer patients, carried out from 1996-2005, shows that 3.5% of Hispanic women with breast cancer have a mutation in the BRCA1 gene, compared to 8.3% of Ashkenazi Jewish women; 2.2% non-Hispanic white women; 1.3% black women; and .5% Asian women.

When looking at women diagnosed before age 35, young black women show a high prevalence of the gene mutation (16.7%), compared to 66.7% Ashkenazi Jewish women; 8.9% Hispanic women; 7.2% non-Hispanic whites, and 2.4% Asian women.

Researchers hypothesize that Hispanic and Ashkenazi Jewish women may share a common ethnic background, stretching back to the time when Spain was home to Sephardic Jews, who may have shared the BRCA1 mutation with Ashkenazi (eastern European) Jews. Many Sephardic Jews converted to Catholicism as a result of the Spanish Inquisition, and some of them moved to the New World, ancestors of a number of Hispanic women today.

Researchers were unable to offer any opinions as to why the mutation is so high in young black women with breast cancer.

Bottom line, the results of this study point to a need for more testing of those most likely to carry BRCA1 gene mutations. Currently, only 10% of such testing, which has been available for about 10 years, is done on minority populations. Women who test positive for BRCA1 often choose to have their ovaries removed, which significantly reduces their risk of breast cancer. They may also have preventive mastectomies. And, even without choosing surgery, at the very least these women are aware of their high risk, and therefore vigilant about mammograms and watching for changes in their breasts.

But what about Hispanic and young black women, who it now appears are also at increased risk–but may not know it? Dr. Olufunmilayo Olopade, professor of medicine and human genetics at the University of Chicago, wrote an editorial accompanying the JAMA article. She noted that “A lot of young women die of breast cancer because they’re not even aware that lump in their breast could be cancer. If you know you’re at high risk, you’ll get that evaluated.”