Relationship between single nucleotide polymorphism of estrogen receptor gene and endocrine therapy efficacy in breast cancer

1113 Objective: To explore the distribution of single nucleotide polymorphism (SNP) loci of estrogen receptor (ESR1) gene in breast cancer patients and to study the relationship between the SNP genotypes and the efficacy to endocrine therapy. Methods: Fifteen SNP loci ( rs872921 , rs2077647, rs3904766, rs2234693, rs11155816, rs827419 , rs2347867, rs3798759, rs1801132, rs985191 , rs9340931, rs9397463, rs722209 , rs3778099, and rs3798577) of ESR1 gene were selected as genetic markers. PCR-restriction fragment length polymorphisms, PCR-DNA sequencing and allele-specific real time PCR methods were employed to analyze the loci genotype of 240 patients with breast cancer accepted endocrine therapy. Results: The loci rs872921 and rs3904766 were abandoned for poor ploymorphisms, and the other 13 loci had polymorphisms. The frequencies of alleles and genotypes of rs2077647 and rs3798759 were significantly related with the efficacy of endocrine therapy (p < 0. 05). The linkage disequilibrium and the hapotype analysis showed that there were four linkage disequilibrium blocks in ESR1 gene. They were rs2077647∼rs2234693 (LD1), rs2234693∼rs11155816 (LD2), rs9397463∼ rs722209 (LD3), and rs3778099∼rs3798577 (LD4), and the hapotypes of LD2, LD3, s11155816- rs827419 , and rs2347867- rs1801132 were positively related with the efficacy of endocrine therapy (p < 0. 05). Conclusions: Some of the polymorphisms of ESR1 gene and the haplotypes are positively associated with the endocrine therapy efficacy, and maybe account for predicting the endocrine response in breast cancer. No significant financial relationships to disclose.