Vitamin D receptor gene polymorphisms and male breast cancer risk in Turkish population

Purpose: Male breast cancer (MBC) is a rare disease. However; as global populace ages, there is a trend for MBC increase. Although its etiology is still unclear, constitutional, environmental, hormonal (abnormalities in estrogen/androgen balance) and genetic (positive family history, Klinefelter syndrome, mutations in BRCA1 and BRCA2) risk factors are already known. One potential target is the vitamin D receptor (VDR). We have investigated whether polymorphisms in the VDR gene are associated with altered MBC risk in a Turkish population. Methods: We recruited 25 men with known breast cancer and 96 men selected from blood donations. Polymorphic sites in VDR gene ApaI (rs7975232), Taq1 (rs731236) and FokI (rs10735810) were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Results: The unconditional logistic regression analysis demonstrated no significant association for the VDR ApaI (p=0.70), TaqI polymorphism (p=0.88) and FokI polymorphism (p=0.075). Conclusion: Our results do not support potential effects of VDR polymorphisms on MBC risk and possible differential effects of receptor status of the tumor However; further studies focusing on the influence of polymorphisms and haplotypes on VDR functionality, activity and concentration are needed.