Polymorphisms in the vitamin D receptor gene and the lung cancer risk

The relationship between the vitamin D receptor (VDR) polymorphisms and the susceptibility to lung cancer remains unclear. The present meta-analysis was performed to estimate the polymorphisms of VDR and lung cancer risk. The pooled odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were calculated. Subgroup analysis by smoking status was carried out for further elucidation. The VDR BsmI polymorphism seemed to be negatively associated with the lung cancer risk (A vs. G, OR = 0.71, 95 % CI, 0.52-0.96; GA vs. GG, OR = 0.54, 95 % CI, 0.35-0.83; AA + GA vs. GG, OR = 0.55, 95 % CI, 0.36-0.84), particularly among the smokers (AA + GA vs. GG, OR = 0.39, 95 % CI, 0.21-0.72). The VDR ApaI variant genotypes did not alter the risk of lung cancer under all gene models in overall analysis. However, smokers carrying the variant G allele were more susceptible to lung cancer (G vs. T, OR = 1.60, 95 % CI, 1.14-2.25). The polymorphism of VDR TaqI was related to a decreased risk of lung cancer (C vs. T, OR = 0.62, 95 % CI, 0.26-1.46; CC vs. TT, OR = 0.44, 95 % CI, 0.21-0.91; TC vs. TT, OR = 0.58, 95 % CI, 0.38-0.90; CC + TC vs. TT, OR = 0.55, 95 % CI, 0.36-0.84). Besides, the CC + TC carriers in the smokers were at a significantly reduced risk of lung cancer (CC + TC vs. TT, OR = 0.48, 95 % CI, 0.16-1.44). The study supports that the polymorphisms of VDR BsmI and TaqI play protective roles in the lung carcinogenesis, particularly among the smokers. The association of VDR ApaI polymorphism with the lung cancer risk needs to be further elucidated.