Meta-analysis on Vitamin D Receptor TaqI Polymorphism and Breast Cancer Risk

Vitamin D receptor (VDR) principally mediates the anticancer activities of vitamin D. Many studies investigated the association between VDR gene TaqI polymorphism and breast cancer, but the results were inconclusive. We performed this meta-analysis to evaluate the association between VDR gene TaqI polymorphism and breast cancer. 21 studies with a total of 10232 cancer cases and 11708 control subjects were identified from PubMed, Embase, Ovid Medline and CNKI databases. The pooled odds ratio (OR) and confidence intervals (95 % CI) were used to assess the association. The meta-analysis indicated that VDR gene TaqI polymorphism was associated with risk of breast cancer (T vs. t, OR = 0.94, 95 % CI 0.91–0.98, p = 0.004; TT vs. tt, OR = 0.88, 95 % CI 0.80–0.95, p = 0.002; TT vs. Tt, OR = 0.98, 95 % CI 0.92–1.04, p = 0.445; TT vs. Tt+tt OR = 0.95, 95 % CI 0.90–1.01, p = 0.078; TT+Tt vs. tt, OR = 0.89, 95% CI .82-0.96, p = 0.002). Subgroup analysis by ethnicity further showed the polymorphism of VDR TaqI was a potential risk factor for breast cancer in the Caucasian population (OR T vs. t = 0.94, 95 % CI 0.91–0.98, p = 0.004; OR TT vs. tt = 0.88, 95%CI 0.81–0.97, p = 0.002).