Background: Estrogen hormone regulates cell proliferation in breast tissue physiologically. Evidences show that changes in estrogen signaling pathways, including the receptor alpha (ER&alpha), happen during breast cancer progression. ER&alpha is expressed in most breast tumors and its association with the development of low-grade tumors has been demonstrated. Single nucleotide polymorphisms (SNPs) in genes may differ in susceptibility to cancer and result in different respond to treatment in different populations. The present study aimed investigated the association between single nucleotide polymorphisms (rs2234693: C/T) in gene ESR&alpha in patients with breast cancer.

Materials and Methods: In this case-control study 150 women with breast cancer and 142 healthy women without a family history of breast cancer were enrolled. DNA was extracted from blood samples. After primer design, technique of PCR-RFLP was used and samples were genotyped by acrylamide gel electrophoresis. Statistical analyzes were performed using SPSS version 20 and chi square test and Final findings were specified.

Results: TT and CT genotypes for ra2234693: C/T site compared with the CC had 5.5 and 1.5-fold increased risk respectively. Statistically significant differences were found between cases and controls for fibrocystic disease and age at menarche.

Conclusion: We not found an association between C/T polymorphism and breast cancer. But CC and TT genotypes of this polymorphism in estrogen receptor alpha gene related with breast cancer that are consistent with the findings of some other researchers.