The Arg194Trp polymorphism in the X-ray repair cross-complementing group 1 gene as a potential risk factor of oral cancer: a meta-analysis.

Polymorphisms in the X-ray repair cross-complementing group 1 (XRCC1) gene have been reported as a potential risk factor for the development of oral cancer; however, the overall results are still controversial. In the present study, we therefore performed a meta-analysis of eight case-control studies that examined the association of oral cancer with XRCC1 gene polymorphisms in different populations, including codon 194 (Arg-Trp), 280 (Arg-His) and 399 (Arg-Gln), based on the data identified in Medline of up to June 2008. Literature-based searching was conducted to gather data and both fixed-effects and random-effects model were used to pool the odds ratio (OR). Publication bias and between-study heterogeneity were also evaluated. The eligible studies included 1,326 cases and 3,130 controls. The OR of various comparisons showed that the oral cancer risk was not associated with the selected three XRCC1 polymorphisms (P > 0.05). However, after stratification, significant association was found between the XRCC1 Arg194Trp polymorphism and oral cancer risk among Asians, showing an OR of 1.347 (95% confidence interval (CI): 1.000, 1.814) for allele comparison, 1.378 (95% CI: 1.070, 1.775) for TT homozygotes versus CC homozygotes, and 1.420 (95% CI: 1.041, 1.936) for comparison under the dominant model. Publication bias was not shown around the studies; however, ORs among these three polymorphisms all yielded significant between-study heterogeneity (P < 0.05) and a part of the heterogeneity was from ethnic differences. We suggest that the Arg194Trp polymorphism in the XRCC1 gene may be a biomarker of oral cancer susceptibility among Asian population.