X-ray repair cross-complementing gene 1 Arg399Gln polymorphism and glioma risk among Asians: A meta-analysis based on 2 326 cases and 3 610 controls★

OBJECTIVE: Previous reports have demonstrated that X-ray repair cross-complementing gene 1 (XRCC1) Arg399Gln polymorphism is a possible risk factor for several cancers. Published data on the association of XRCC1 Arg399Gln polymorphism with glioma susceptibility have generated conflicting results. This study is designed to precisely estimate the relationship. DATA RETRIEVAL: A computer-based online retrieval of Medline, EMBASE, OVID, Sciencedirect, and Chinese National Knowledge Infrastructure was performed to search papers regarding association of XRCC1 Arg399Gln polymorphisms with glioma published up to April 2012. SELECTION CRITERIA: Two investigators selected data independently. Meta analysis was then performed for the selected studies using STATA 11.0 software after strict selection. Heterogeneity test, sensitivity analysis and publication bias assessments were then conducted. MAIN OUTCOME MEASURES: Association of XRCC1 Arg399Gln polymorphism with glioma risk. RESULTS: A total of nine case-controlled studies comprising 2 326 cases and 3 610 controls were selected for final analysis. The overall data failed to indicate a significant association of XRCC1 Arg399Gln polymorphism with glioma risk (Gln/Gln vs. Arg/Arg: odds ratio (OR) = 1.11; 95% confidence interval (CI) = 0.94–1.31; dominant model: OR = 1.06; 95%CI = 0.95–1.18; recessive model: OR = 1.04; 95%CI = 0.81–1.34). However, subgroup analysis regarding ethnicity showed an increased risk among Asians (Gln/Gln vs. Arg/Arg: OR = 1.70; 95%CI = 1.17–2.46; dominant model: OR = 1.40; 95%CI = 1.10–1.78; recessive model: OR = 1.46; 95%CI = 1.04–2.05) but not Caucasians or mixed ethnicities. CONCLUSION: XRCC1 Arg399Gln polymorphism might modify the susceptibility to glioma among Asians but not Caucasians. Further large and well-designed studies are needed to confirm this conclusion.