Common variants of vitamin D receptor gene polymorphisms and risk of gastric cancer: A meta-analysis

Background: While earlier studies have suggested that variations in the vitamin D receptor (VDR) gene could influence the susceptibility to gastric cancer (GC), the results have shown inconsistency. This meta-analysis aimed to examine the association of 5 common polymorphisms in VDR, including Taq1 rs731236 (T > C), FokI rs2228570 (C > T), Cdx2 rs11568820 (G > A), BsmI rs1544410 (G > A), and ApaI rs7975232 (G > T) with the risk of GC. Methods: A comprehensive search was carried out in PubMed, Web of Science, and Scopus to identify relevant studies published until January 2024. Odds ratios (ORs) with 95% confidence intervals (CIs) were utilized to assess the magnitude of associations. Results: Nine studies, with 2837 participants (1215 GC cases and 1622 healthy controls), were eligible. The FokI rs2228570 polymorphism showed a significant correlation with heightened susceptibility to GC under the recessive model (OR = 1.52; 95% CI: 1.06-2.19) and homozygote comparison (TT vs CC; OR = 1.59; 95% CI: 1.09-2.31). Taq1 rs731236 was also linked to an elevated risk of GC under the same models (recessive OR = 1.65; 95% CI: 1.14-2.39; homozygote OR = 1.68; 95% CI: 1.11-2.54). In the sensitivity analysis, when studies not adhering to Hardy-Weinberg equilibrium were excluded, the relationship between FokI rs2228570 polymorphism and GC disappeared, while the association for Taq1 rs731236 remained consistent. No significant association was identified for BsmI rs1544410, ApaI rs7975232, and Cdx2 rs11568820. Conclusion: This study revealed that FokI rs2228570 and Taq1 rs731236 polymorphisms of VDR might be linked to the odds of GC.