Abstract

Two non-synonymous polymorphisms Arg194Trp and Arg399Gln in the DNA-base excision repair gene X-ray repair cross-complementing group 1 (XRCC1) have been implicated in risk for esophageal cancer. However, the results from different studies remain controversial. The present meta-analysis of literatures was performed to clarify these associations in Chinese population. A comprehensive literature search was conducted to identify all case-control studies of XRCC1 polymorphisms Arg194Trp and Arg399Gln and risk for esophageal squamous cell carcinoma (ESCC). A total of 9 eligible studies, including 1,538 ESCC cases and 2,472 controls, were identified to the meta-analysis. The odds ratio (OR) for the variant homozygous genotype Trp/Trp of the Arg194Trp polymorphism, compared with the wild-type homozygote Arg/Arg, was 1.59 (p = 0.0007), with 95% confidence interval (95% CI) 1.22-2.09, for ESCC risk without between-study heterogeneity. However, there was no statistically significant associations of ESCC risk in the dominant model Arg/Trp+Trp/Trp (OR 0.97; 95% CI 0.84-1.12; p = 0.69) and heterozygous genotype Arg/Trp (OR 0.90; 95% CI 0.77-1.04; p = 0.16) when comparing with wild-type genotype Arg/Arg. For Arg399Gln, there was no effect in dominant modeling (Arg/Gln+Gln/Gln vs. Arg/Arg: OR 0.92; 95% CI 0.80-1.06; p = 0.25), and the variant Gln/Gln homozygote was not associated with ESCC risk (OR 1.29; 95% CI 0.79-2.10; p = 0.31), either. In conclusion, Arg194Trp genetic polymorphism may be associated with an increased risk for developing ESCC and a study with the larger sample size is needed to further evaluate gene-environment interaction on XRCC1 polymorphisms and ESCC risk.

2009 UICC.