Introduction: Vitamin D fulfills its crucial role in cell proliferation and death through signal transduction into the nucleus by vitamin D receptor (VDR). Recent studies have depicted the association between VDR gene polymorphisms and different cancers, including breast cancer. This study attempted to consider the relationship between VDR gene polymorphisms and breast cancer risk among women in West Azerbaijan Province, Iran. Methods: FokI and BsmI polymorphisms were studied through the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique on blood samples taken from 95 cancer and 71 healthy participants from Urmia City. The association between the mentioned polymorphisms and breast cancer risk was considered using calculated odds ratio (OR). Results: The findings showed the protective effect of the FokI polymorphism in breast cancer development (OR = 0.2731), while no statistically significant correlation was observed between breast cancer and BsmI polymorphism (P > 0.05). Conclusions: This study identified the protective effect of the FokI polymorphism in breast cancer, and the absence of statistically significant association between BsmI polymorphism and breast cancer.

Background: Recently, findings have validated the significant role of DNA damage genes related to the pathogenesis of breast cancer (BC). The aim of the present investigation was to evaluate possibility roles of two common XRCC1 (rs25487; A > G) and ERCC1 (rs3212964; A > G) gene polymorphisms with the risk of sporadic BC. Methods: This was a case-control study, consisting of 100 females identified with sporadic BC and 100 malignancy-free females as the control group. This study used Tetra-ARMS Polymerase Chain Reaction (PCR) and PCR-Restriction Fragment Length Polymorphism (RFLP) methods to determine genotype frequencies of XRCC1 and ERCC1 genes. Results: The findings did not reveal a statistically significant difference in the genotype frequencies of XRCC1 and ERCC1 genes between the two groups (P > 0.05). The frequency of G mutant allele for XRCC1 and ERCC genes was higher in cases compared to controls, while the difference between the groups was not statistically significant (P = 0.202; OR: 1.312; CI: 0864 -1.994), (P = 0.352; OR: 1.213; CI: 0.808 -1.820). Conclusions:The current results provide evidence against the hypothesis that XRCC1 (rs25487) and ERCC1 (rs3212964) gene polymorphisms may be associated with a predisposition to sporadic BC.