Vitamin D status, receptor gene BsmI (A/G) polymorphism and breast cancer in a group of Egyptian females

Abstract

BackgroundVitamin D is involved in a wide variety of biological processes including bone metabolism, modulation of the immune response, and regulation of cell proliferation and differentiation. The present study aimed to investigate vitamin D status and the genetic polymorphism BsmI (A/G) of vitamin D receptor (VDR) among a group of Egyptian female patients with breast cancer. MethodsThe current study included 60 female patients diagnosed as breast cancer (BC) attending Mansoura Oncology Center, Mansoura University, and 60 age-matched healthy control females. Serum 25(OH) vitamin D level was measured using Enzyme-linked immunosorbent assay (ELISA) kit. A polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) method and fragment analysis were performed to determine the VDR BsmI (A/G) polymorphism. Results25(OH) vitamin D levels were significantly lower in the patients with BC (22.1±10.9ng/ml) compared to controls (41.2±11.22ng/ml) (p⩽0.001). Vitamin D deficiency- insufficiency was reported in 76.7% of BC patients and 20% of the controls (P⩽0.001, OR=13.1, 95%CI=5.5−31.4). Bb genotype was statistically higher in the BC patients than in the healthy controls (P⩽0.001). 81.2% of BC patients were of Bb genotype, 10.9% of BB genotype and 4.3% of bb genotype, while in controls, 33.3% for each genotype. No statistically significant difference in allele frequency was observed between the two studied groups. Carriers of Bb genotype had 4.6times increased risk of developing breast cancer (95% confidence interval of 2.0–10.3) when compared to other genotypes. ConclusionA significant association exists between vitamin D deficiency and the risk of breast cancer. B allele or Bb genotype of VDR may be a susceptibility risk factor for BC development.