RESUMEN
INTRODUCTION: Breast cancer is a leading cause of cancer morbidity and mortality in females. Decreased availability of Vitamin D within breast cells, contributed by deficiency of serum Vitamin D and polymorphisms of Vitamin D receptor genes are possible risk factors for breast cancer. OBJECTIVES: To study the association of FokI polymorphism of the Vitamin D Receptor gene with breast cancer in females and to study the levels of Vitamin D in breast cancer patients. MATERIALS AND METHODS: VDR gene FokI genotyping was done by PCR-RFLP method and levels of serum Vitamin D were estimated by ELISA. Statistical analysis was done with SPSS v.21. RESULTS: Serum Vitamin D was significantly lower in newly diagnosed breast cancer patients than in healthy controls (P = 0.016). Females with serum Vitamin D levels in the highest quartile have a lesser risk of breast cancer than those with serum Vitamin D levels in the lowest quartile (O. R = 2.4421, C.I = 1.09-5.45, P = 0.029). The risk of developing breast cancer is higher in women with the polymorphic T allele for VDR FokI genotype (CT/TT) than those homozygous for the wild C allele (CC). (O.R. = 4.295, C.I. = 2.2110-8.3451, p-value = <0.0001). Levels of serum Vitamin D were significantly higher (p < 0.001) in ER + patients and significantly low in those presenting with higher stages of cancer (p = 0.009). CONCLUSIONS: FokI polymorphism of VDR gene and low circulating Vitamin D levels increase the risk of developing breast cancer in North Indian females. Serum Vitamin D can be used as a prognostic factor.