The association of vitamin D receptor gene polymorphism with lung cancer risk: an update meta-analysis.

The association between vitamin D receptor (VDR) genetic polymorphism and lung cancer risk has been evaluated by previous meta-analyses. Due to emergence of novel studies and inappropriate inclusion of overlapping populations, an update meta-analysis on recent evidences is necessarily needed. We comprehensively searched databases of PubMed, Web of Science and Chinese National Knowledge Infrastructure and finally obtained 7 eligible studies according to the inclusion criteria. Four positions on VDR gene, namely ApaI (rs7975232), BsmI (rs1544410), FokI (rs10735810) and TaqI (rs731236), were considered in this investigation. Data pooling found no significant association of lung cancer risk with ApaI or FokI. In contrast, it was indicated that the BsmI A allele was negatively related to the lung cancer risk, compared with the G allele (OR = 0.51, 95% CI = 0.33-0.79). Individuals with BsmI AA (OR = 0.53, 95% CI = 0.26-1.11) and AG genotypes (OR = 0.46, 95% CI = 0.30-0.71) showed decreased risk of lung cancer, compared with those with GG genotype. Regarding the TaqI polymorphism, the T allele carriers were at increased risk of lung cancer (OR = 1.25, 95% CI = 1.04-1.50). Compared with the TaqI TC+CC genotype, the TT genotype was positively associated with lung cancer risk (OR = 1.42, 95% CI = 1.11-1.82). No publication bias was identified in any of the analysis. In conclusion, VDR genetic polymorphism may be correlated to lung cancer risk. Given limited number of the included studies, more observations are warranted to draw a safer conclusion.