Evaluation of 19 Susceptibility Loci of Breast Cancer in Women of African Ancestry

Carcinogenesis. 2012 Apr;33(4):835-40. doi: 10.1093/carcin/bgs093. Epub 2012 Feb 22.

Abstract

Multiple breast cancer susceptibility loci have been identified in genome-wide association studies (GWAS) in populations of European and Asian ancestry using array chips optimized for populations of European ancestry. It is important to examine whether these loci are associated with breast cancer risk in women of African ancestry. We evaluated 25 single nucleotide polymorphisms (SNPs) at 19 loci in a pooled case-control study of breast cancer, which included 1509 cases and 1383 controls. Cases and controls were enrolled in Nigeria, Barbados and the USA; all women were of African ancestry. We found significant associations for three SNPs, which were in the same direction and of similar magnitude as those reported in previous fine-mapping studies in women of African ancestry. The allelic odds ratios were 1.24 [95% confidence interval (CI): 1.04-1.47; P = 0.018] for the rs2981578-G allele (10q26/FGFR2), 1.34 (95% CI: 1.10-1.63; P = 0.0035) for the rs9397435-G allele (6q25) and 1.12 (95% CI: 1.00-1.25; P = 0.04) for the rs3104793-C allele (16q12). Although a significant association was observed for an additional index SNP (rs3817198), it was in the opposite direction to prior GWAS studies. In conclusion, this study highlights the complexity of applying current GWAS findings across racial/ethnic groups, as none of GWAS-identified index SNPs could be replicated in women of African ancestry. Further fine-mapping studies in women of African ancestry will be needed to reveal additional and causal variants for breast cancer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • African Continental Ancestry Group / genetics*
  • Breast Neoplasms / ethnology
  • Breast Neoplasms / genetics*
  • Case-Control Studies
  • Female
  • Genetic Predisposition to Disease*
  • Genome-Wide Association Study
  • Humans
  • Middle Aged
  • Polymorphism, Single Nucleotide