Publication date: November 7, 2012
According to findings from the Black Women’s Health Study, certain genetic variants and a higher percentage of African ancestry were linked with an increased risk of triple-negative breast cancer. These results were published in Cancer Epidemiology, Biomarkers & Prevention.
African-American women are known to have a higher risk of triple-negative breast cancer than white women, but the reasons for this increased risk are not well understood. To explore certain genetic factors that may increase risk, researchers evaluated a subset of women who participated in the Black Women’s Health Study. The analysis included 1,199 women with breast cancer and a comparison group of 1,948 women without breast cancer.
The researchers collected DNA from the study participants and evaluated small genetic variations known as single-nucleotide polymorphisms (SNPs). The study focused on 24 SNPs that had previously been linked with breast cancer. The studies that originally identified these SNPs had focused primarily on women of European or Asian ancestry, leaving some question about whether and how they affect risk in women of African Ancestry.
Evaluation of DNA also allowed the researchers to estimate the percentage of African ancestry for each of the study participants.
- Two SNPs that had previously been linked with triple-negative breast cancer were also linked with triple-negative breast cancer in this study. These SNPs increased the risk of triple-negative breast cancer by 42 to 48 percent.
- One of these SNPs appears to be more common in African-American women than in other women; this may partially explain why African-American women are more likely to get triple-negative breast cancer.
- Women with a higher percentage of African ancestry also had an increased risk of triple-negative breast cancer.
According to the researchers, these findings “demonstrate the importance of genetic factors in the disproportionately high occurrence of TNBC in African American women.” This type of research increases our understanding of the biology of triple-negative breast cancer, and may provide clues to the prevention and treatment of this condition.