The correlation between genetic ancestry, hormone replacement therapy use, and breast feeding behavior partially explain an interaction between a breast cancer risk variant and genetic ancestry in Hispanic women. This according to a study of 10 single nucleotide polymorphisms (SNPs) identified through genome-wide association studies in 2,107 Hispanic women with breast cancer and 2,587 unaffected controls. Researchers found that SNP Rs13387042-2q35(G/A) was associated with breast cancer risk only among:

• Postmenopausal women who never used hormone therapy. Odds ratios were 0.94, 1.20, and 1.49 for current hormone therapy users, previous users, and never users, respectively.

• Premenopausal women who breastfed > 12 months. Odds ratios were 1.01, 1.19, and 1.69 for women who never breastfed, breastfed < 12 months, and > 12 months, respectively.

Citation: Fejerman L, Stern MC, John EM, et al. Interaction between common breast cancer susceptibility variants, genetic ancestry, and non-genetic risk factors in Hispanic women. [Published online ahead of print September 12, 2015]. Cancer Epidemiol Biomarkers Prev. doi: 10.1158/1055-9965.EPI-15-0392.