The distribution pattern of ERα expression, ESR1 genetic variation and expression of growth factor receptors: association with breast cancer prognosis in Russian patients treated with adjuvant tamoxifen
Breast cancer is a heterogeneous disease which is influenced by genetic, environmental, and lifestyle factors. Genetic susceptibility is likely to be due to variants conferring more moderate risks. To identify susceptibility alleles, we conducted a case–control association study in 185 breast cancer cases and 199 controls in the Han population. We genotyped 14 tagging single nucleotide polymorphisms previously implicated in breast cancer using Sequenom MassARRAY SNP genotyping method and identified rs3734805 in the ESR1 gene and rs2048672 in the FLJ43663 gene were associated with breast cancer risk. Allele “C” of rs3734805 was associated with increased breast cancer progression by χ 2 test and additive model analysis (OR = 1.36; 95 % CI, 1.01–1.82; p = 0.042). Using recessive model analysis, we found that genotype “GG” of rs2048672 was the protective genotype during breast cancer progression (OR = 0.55; 95 % CI, 0.32–0.95; p = 0.029). Our results provide additional insights into the opposing roles of the ESR1 and FLJ43663 genes in breast cancer onset and progression.