Impact of ESR1 Polymorphisms on Risk of Breast Cancer in the Chinese Han Population.

Background: The estrogen receptor-1 (ESR1) gene encodes estrogen receptor-α, which is a major biomarker in the development of breast cancer. This study aimed to investigate the effect of ESR1 polymorphisms on breast cancer in Chinese Han women.

Materials And Methods: We genotyped 4 candidate single nucleotide polymorphisms (SNPs) in ESR1 among 503 patients with breast cancer and 503 healthy people using the Agena MassARRAY platform. The association between ESR1 polymorphisms and breast cancer risk was evaluated using odds ratios (ORs) and 95% confidence intervals (95% CIs) under 4 genetic models. The HaploReg v4.1 and GEPIA database were used for SNP functional annotation and ESR1 expression analysis, respectively.

Results: The T allele of rs9383938 in ESR1 was significantly associated with an increased breast cancer risk (OR, 1.26; 95% CI, 1.05-1.50; P = .013). In genetic models, rs9383938 increased breast cancer risk in the codominant model (OR, 1.54; 95% CI, 1.07-2.22; P = .021), the dominant model (OR, 1.31; 95% CI, 1.01-1.68; P = .040), and the additive model (OR, 1.24; 95% CI, 1.04-1.48; P = .017). Stratification analysis showed that rs9383938 and rs2228480 raised the breast cancer susceptibility in individuals aged younger than 52 years old. Rs1801132 of ESR1 was significantly associated with the status of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 in the allele model and genetic models (P < .05).

Conclusions: This study demonstrated that ESR1 polymorphisms might influence breast cancer susceptibility in the Chinese Han population. Further mechanism studies are needed to confirm the contribution of ESR1.