Association between polymorphisms in XRCC4 gene and glioma risk: a meta-analysis and systematic review

Objective: Increasing evidences have shown that DNA repair molecule related genes can be cancer-risk genes. In recent, polymorphisms in XRCC4, which is a member of DNA repair genes, have been identified contributed to the risk of a variety of cancers, including glioma. Nevertheless, data derived from these studies are inconclusive. Therefore, to obtain a more precise estimation, the present meta-analysis was conducted. Methods: A comprehensive retrieve was conducted to identify all eligible studies concerning XRCC4 polymorphisms and glioma risk. Odds ratios (ORs) correspondence with 95% confidence intervals (CIs) were applied to evaluate the strength of associations. Results: We included seven publications comprising 12 case-control studies including 3,199 cases and 5,340 controls concerning two polymorphisms (rs1805377 and rs3734091) in XRCC4 and glioma risk. Overall, significant association was uncovered for rs1805377 polymorphism and risk of glioma (BB VS. AA: OR=1.372, 95% CI: 1.061-1.775, P=0.016; BB VS. BA+AA: OR=1.346, 95% CI: 1.054-1.721, P=0.017). In addition, we also uncovered an increased risk of glioma for rs3734091 polymorphism (BA VS. AA: OR=1.379, 95% CI: 1.052-1.808, P=0.020). When subgroup analysis was performed by ethnicity, we identified a significantly increased risk for glioma of rs1805377 polymorphism (BB VS. AA: OR=1.363, 95% CI: 1.045-1.778, P=0.022; BB VS. BA+AA: OR=1.333, 95% CI: 1.035-1.716, P=0.026), as well as rs373409 polymorphism in Asian population (BA VS. AA: OR=1.442, 95% CI: 1.085-1.916, P=0.012). Conclusions: Our work suggests that rs1805377 and rs3734091 polymorphisms in XRCC4 might be risk factors of glioma. Nevertheless, future well-designed studies are warranted to explore the molecular mechanisms underlying the biological functions of XRCC4 polymorphisms in glioma development.