The XRCC1 Arg194Trp polymorphism is not a risk factor for glioma: A meta-analysis involving 1,440 cases and 2,562 controls

Previous reports have indicated that the X-ray repair cross-complementing gene 1 (XRCC1) Arg194Trp polymorphism may be a risk factor for several types of cancer. Published studies on the association of XRCC1 Arg194Trp polymorphisms with glioma risk have yeilded conflicting results. The present study aimed to obtain a more precise estimation of this association. Meta-analyses assessing the association of the XRCC1 Arg194Trp variation with glioma were conducted and subgroup analyses based on ethnicity and source of controls were also performed. Eligible studies were identified during the period before May 2012. A total of four case-control studies comprising 1,440 cases and 2,562 controls were finally selected for analysis. The overall data failed to indicate a significant association of the XRCC1 Arg194Trp polymorphism with glioma risk [Trp vs. Arg: odds ratio (OR) = 1.01, 95% confidence interval (95% CI) = 0.77-1.33; Trp/Trp vs. Arg/Arg: OR = 1.56, 95% CI = 0.96-2.54; dominant model: OR = 0.98, 95% CI = 0.74-1.31; recessive model: OR = 1.48, 95% CI = 0.92-2.38]. Similarly, in the subgroup analysis based on ethnicity and source of controls, no associations were observed. In conclusion, the results of the present study failed to suggest an association between the XRCC1 Arg194Trp polymorphism and glioma risk. Further large and well-designed studies are required to confirm this conclusion.