XRCC1 Arg399Gln polymorphism is not associated with oral cancer risk: evidence from a meta-analysis.

Previous studies regarding the association between X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism and oral cancer risk were contradictory. We performed a meta-analysis to derive a more precise estimation of the association. The PubMed and Web of Science were searched for eligible studies. Odds ratio (OR) with its 95% confidence interval (95% CIs) was used to assess the strength of the association. Nine individual studies with a total of 3,244 subjects were finally included into the meta-analysis. Overall, there was no association between XRCC1 Arg399Gln polymorphism and oral cancer risk under all genetic models (Gln versus Arg: OR = 1.09, 95% CI 0.86-1.37, P = 0.46; GlnGln versus ArgArg: OR = 1.11, 95% CI 0.69-1.79, P = 0.66; GlnGln versus ArgArg/ArgGln: OR = 1.04, 95% CI 0.68-1.61, P = 0.84; and GlnGln/ArgGln versus ArgArg: OR = 1.13, 95% CI 0.88-1.44, P = 0.34). After excluding studies on oral leukoplakia, there was still no association between XRCC1 Arg399Gln polymorphism and oral cancer risk under all genetic models. Subgroup analysis by ethnicity suggested that there was no association between XRCC1 Arg399Gln polymorphism and oral cancer risk in both Asians and Caucasians. In conclusion, the data from the meta-analysis suggests that XRCC1 Arg399Gln polymorphism is not associated with oral cancer risk.