XRCC1 Gene Polymorphisms and Glioma Risk in Chinese Population: A Meta-Analysis

BACKGROUND Three extensively investigated polymorphisms (Arg399Gln, Arg194Trp, and Arg280His) in the X-ray repair cross-complementing group 1 (XRCC1) gene have been implicated in risk for glioma. However, the results from different studies remain inconsistent. To clarify these conflicts, we performed a quantitative synthesis of the evidence to elucidate these associations in the Chinese population. METHODS Data were extracted from PubMed and EMBASE, with the last search up to August 21, 2014. Meta-analysis was performed by critically reviewing 8 studies for Arg399Gln (3062 cases and 3362 controls), 8 studies for Arg194Trp (3419 cases and 3680 controls), and 5 studies for Arg280His (2234 cases and 2380 controls). All of the statistical analyses were performed using the software program, STATA (version 11.0). RESULTS Our analysis suggested that both Arg399Gln and Arg194Trp polymorphisms were significantly associated with increased risk of glioma (for Arg399Gln polymorphism: Gln/Gln vs. Arg/Arg, OR = 1.82, 95% CI = 1.46-2.27, P = 0.000; Arg/Gln vs. Arg/Arg, OR = 1.25, 95% CI = 1.10-1.42, P = 0.001 and for Arg194Trp polymorphism: recessive model, OR = 1.78, 95% CI = 1.44-2.19, P = 0.000), whereas the Arg280His polymorphism had no influence on the susceptibility to glioma in a Chinese population. CONCLUSIONS This meta-analysis suggests that there may be no association between the Arg280His polymorphism and glioma risk, whereas the Arg399Gln/Arg194Trp polymorphisms may contribute to genetic susceptibility to glioma in the Chinese population. Nevertheless, large-scale, well-designed and population-based studies are needed to further evaluate gene-gene and gene-environment interactions, as well as to measure the combined effects of these XRCC1 variants on glioma risk.