In an ambitious pursuit to unravel the unique genetic risks associated with breast cancer among women of African descent, a research team led by Dr. Wei Zheng of Vanderbilt University has meticulously analyzed genetic data from over 40,000 individuals within this population.
The study, believed to be the largest genome-wide association study (GWAS) of its kind, sought to identify genetic variants more prevalent in participants with breast cancer compared to those without. According to the National Institutes of Health, the analysis unveiled 12 genetic regions, or loci, associated with the disease, three of which were specifically linked to the aggressive triple-negative subtype, which Black women are twice as likely to develop compared to whites.
An alarming 8% of the study participants harbored two copies of the high-risk genetic variants within all three of the identified loci, elevating their probability of developing the aggressive triple-negative breast cancer subtype by a staggering 4.2-fold in comparison to women possessing only one or lacking any copies of these concerning variants.
Dr. Zheng emphasized the significance of these findings, stating, “Data put together in this consortium have been and will continue to be used by researchers around the world.” As triple-negative breast cancer lacks specific cell receptors often targeted in treatment, such as estrogen or HER2 receptors, these insights may pave the way for the identification of new therapeutic targets.
The study also corroborated numerous previously identified breast cancer risk variants across diverse populations and uncovered an uncommon risk variant in ARHGEF38, a gene associated with prostate and lung cancers in the past. The data gathered as part of the NIH-funded African Ancestry Breast Cancer Genetic consortium encompassed 26 studies, with approximately 18,000 participants having been diagnosed with breast cancer. Most (85%) of the participants were African Americans, while the remaining were from Barbados or Africa.
Over 310,000 new breast cancer cases are anticipated to emerge nationwide this year, and Black women are more likely than whites to die from the disease. Results from the study were reported in Nature Genetics on May 13.