Investigation of Triple-Negative Breast Cancer Risk Alleles in An International African-Enriched Cohort

Large-scale efforts to identify breast cancer risk alleles have historically taken place among women on European ancestry, with recent efforts to validate these alleles or identify risk alleles applicable to women of African descent. We investigated the effect of previously reported breast cancer and triple-negative breast cancer (TNBC) risk alleles in our African enriched International Center for the Study of Breast Cancer Subtypes (ICSBCS) cohort. Using case-control and nested case-series approaches, we report that the Duffy-null allele (rs2814778) is associated with TNBC risk (OR = 3.814, p = 0.001), specifically among AA individuals, after adjusting for self-indicated race and west African ancestry (OR = 3.368, p = 0.007). We have also validated the protective effect of the minor allele of the ANKLE1 missense variant rs2363956 among AA for TNBC (OR = 0.4204, p = 0.005). We have shown that differential prevalence of the protective allele may reflect a polymorphic function of ANKLE1 in TNBC breast cancer outcomes. These AA specific risk alleles present opportunities for future studies of therapeutic potential that address race-specific differences in BC and TNBC risk and disease outcome.