Association of VDR gene TaqI polymorphism with the susceptibility to prostate cancer in Asian population evaluated by an updated systematic meta-analysis.

Background: The vitamin D receptor (VDR) plays a key role in vitamin-mediated signaling pathway. Emerging evidence has suggested that the VDR polymorphism may contribute to the risk of prostate cancer (PCa). However, the existing results are not conclusive in Asian population. Methods: We aim to evaluate the potential role of VDR polymorphisms on PCa of Asian population. PubMcd. Scopus, Embase, Web of Science, Chinese National Knowledge Infrastructure, Wang Fang Data, and VIP Periodical were retrieved, and eligible studies (case control or cohort study) meeting the inclusion criteria were evaluated through an updated meta-analysis using Statal3.0 software. Results: A total of 1,363 cases and 2,101 controls obtained from 13 eligible publications were eventually included in this meta-analysis. Our results show that a significant association of VDR taql polymorphism with PCa risk, especially in the Japanese population. In the clinical stage stratified analysis, the pooled results revealed no significant difference in genetic polymorphisms between the local stage and control groups, whereas there was increased frequency of T allele and TT genotype in the advanced tumor stage group compared with local tumor stage or control groups. Similarly, no significant difference was seen in Gleason < 7 and control groups, but the T allele and TT genotype were significantly higher in the Gleason >= 7 group compared with Gleason < 7 or control groups. Conclusion: The VDR Taql polymorphism might be associated with PCa risk in Asian population, especially in the Japanese population. Also, PCa patients carrying the T allele or TT genotype were more likely to progress to advanced stage. These results suggest that VDR Taql polymorphisms may be potential diagnostic biomarkers for PCa susceptibility.