Reappraisal of XRCC1 Arg194Trp polymorphism and glioma risk: a cumulative meta-analysis

The association between XRCC1 Arg194Trp polymorphism and glioma risk were inconsistent from published meta-analyses and epidemiological studies. Hence, we performed this updated and cumulative meta-analysis to reappraisal this relationship. PubMed, Embase, CBM (Chinese Biomedical Database), and CNKI (China National Knowledge Internet) databases were comprehensively searched up to August 13, 2016 (updated on December 22, 2016). After study selection and data extraction from eligible studies, the association was evaluated by odds ratios (ORs) and its 95% confidence intervals (95%CIs) using Comprehensive Meta-Analysis software. Finally 16 case-control studies involving 7011 patients and 9519 healthy controls were yielded. The results indicated that XRCC1 Arg194Trp polymorphism was significantly correlated with the increased risk of glioma [Trp vs. Arg: OR = 1.18(1.05-1.34); TrpTrp vs. ArgArg: OR = 1.66(1.31-2.12); ArgTrp vs. ArgArg: OR = 1.34(1.02-1.77); TrpTrp vs. ArgArg+ArgTrp: OR = 1.47(1.26-1.72); TrpTrp+ArgTrp vs. ArgArg: OR = 1.17(1.01-1.35)]. Cumulative analysis showed the results changed from non-significant to significant when new studies accumulated, and sensitivity analysis indicated the results were stable. Subgroup analysis showed the significant association existed in Asians but not in Caucasians. Current evidence indicated that XRCC1 Arg194Trp polymorphism was associated with increased risk for glioma, especially in Asians; however, relevant studies involving other ethnic groups are required to validate our findings in further.