Variants of estrogen-related genes and breast cancer risk in European and African American women

    1. Song Yao1
    1. 1Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York 14263, USA
      2University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, USA
      3Icahn School of Medicine at Mount Sinai, New York, New York, USA
      4New Jersey Department of Health, Trenton, New Jersey, USA
      5Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey, USA
    1. Correspondence should be addressed to S Yao; Email: song.yao{at}


    It has been observed previously that compared with women of European ancestry (EA), those of African ancestry (AA) are more likely to develop estrogen receptor (ER)-negative breast cancer, although the mechanisms have not been elucidated. We tested the associations between breast cancer risk and a targeted set of 20 genes known to be involved in estrogen synthesis, metabolism, and response and potential gene–environment interactions using data and samples from 1307 EA (658 cases) and 1365 AA (621 cases) participants from the Women’s Circle of Health Study (WCHS). Multivariable logistic regression found evidence of associations with single-nucleotide polymorphisms (SNPs) in the ESR1 gene in EA women (rs1801132, odds ratio (OR)=1.47, 95% CI=1.20–1.80, P=0.0002; rs2046210, OR=1.24, 95% CI=1.04–1.47, P=0.02; and rs3020314, OR=1.43, 95% CI=1.19–1.70, P=0.00009), but not in AA women. The only other gene associated with breast cancer risk was CYP1A2 in AA women (rs2470893, OR=1.42, 95% CI=1.00–2.02, P=0.05), but not in EA women. When stratified by ER status, ESR1 rs1801132, rs2046210, and rs3020314 showed stronger associations in ER-positive than in ER-negative breast cancer in only EA women. Associations with the ESR1 SNPs in EA women also appeared to be stronger with longer endogenous estrogen exposure or hormonal replacement therapy use. Our results indicate that there may be differential genetic influences on breast cancer risk in EA compared with AA women and that these differences may be modified by tumor subtype and estrogen exposures. Future studies with a larger sample size may determine the full contribution of estrogen-related genes to racial/ethnic differences in breast cancer.

    • Revision received 29 August 2014
    • Accepted 16 September 2014
    • Made available online as an Accepted Preprint 16 September 2014
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