Estrogen Receptor Alpha Gene Single Nucleotide Polymorphisms, +2464 C/T and -4576A/C, and Breast Cancer Risk, a Hospital-Based Case-Control Study

Background: Estrogen is a risk factor for the development of breast cancer. The effect of estrogen is primarily mediated by estrogen receptor alpha 1 (ESR1). In this study, we investigated the association between breast cancer risk and the frequency of alleles and genotypes for two ESR1 single nucleotide polymorphisms (SNPs) in breast cancer patients and a healthy control group. Methods: A total of 98 female patients with pathologically confirmed breast cancer and 93 age-matched healthy female controls who were selected from the visitors of the general hospital were recruited in the study. Two ESR1 candidate polymorphisms; +2464 C/T (rs3020314) and -4576 A/C (rs1514348) were selected. The frequency of alleles and genotypes was determined using Quantitative Real-Time PCR assay. Linkage disequilibrium (LD) was assessed for each pair of markers. Using logistic regression, genotype frequencies were estimated as odds ratios with 95% confidence intervals. Results: There was no significant difference in the genotype and allele distributions of ESR1 for SNPs +2464 C/T and SNP -4576 A/C between patients and controls. The frequency of the ESR1 +2464 T/T genotype in case and control groups was 31.6% vs 29.0%, (OR TT/TC: 1.13, 95%CI: 0.58, 2.20; P = 0.69). The frequency of the +2464C allele was 33.9% vs 35.2%, (OR C/T: 0.94, 95%CI: 0.60, 1.47; P =0.79). The frequency of the ESR1 -4576C/C genotype in case and control groups was 37.75% vs 33.36%, OR CC/AC: 1.02, 95%CI: 0.51, 1.97; P =0.98). The frequency of the -4576A allele was 36.2% vs 43.6 %, (OR C/A: 0.73, 95%CI: 0.47, 1.13; P =0.14). Conclusion: The results indicated that ESR1 polymorphism does not show any significant association with breast cancer risk among female Iranian adults.