XRCC1 Arg399Gln polymorphism and bladder cancer risk: updated meta-analyses based on 5767 cases and 6919 controls.

Previous reports implicate XRCC1 Arg399Gln polymorphism as a possible risk factor for several cancers. Published meta-analyses have been conducted on the association of XRCC1 Arg399Gln polymorphism with susceptibility to bladder cancer, and have generated conflicting results. The present study aimed to derive a more precise estimation of the relationship. Updated meta-analyses assessing the association of XRCC1 Arg399Gln polymorphism with bladder cancer were conducted and subgroup analyses on ethnicity, smoking status and source of controls were further performed. Eligible studies were identified for the period up to May 2012. A total of 19 case-control studies comprising 5767 cases and 6919 controls were lastly selected for analysis. The overall data failed to indicate significant associations between XRCC1 Arg399Gln polymorphism and bladder cancer risk (Gln/Gln versus Arg/Arg: odds ratio (OR) = 0.97; 95% CI = 0.85-1.10; dominant model: OR = 1.02; 95% CI = 0.94-1.09; recessive model: OR = 0.95; 95% CI = 0.84-1.07). In subgroup analyses stratified by ethnicity, smoking status and source of controls, respectively, similar results were obtained. In conclusion, the results of the present study suggest that XRCC1 Arg399Gln polymorphism might not modify the susceptibility to bladder cancer. Further large and well-designed studies are needed to confirm this conclusion.