XPC Lys939Gln and Ala499Val polymorphisms in colorectal cancer susceptibility: a meta-analysis of case–control studies

Abstract

The XPC Lys939Gln and Ala499Val polymorphisms were likely to be involved with the development of colorectal cancer. However, there had been inconsistent reports of association. This meta-analysis of literatures was performed to draw a more precise estimation of the relationship. We systematically searched PubMed, Embase and Web of Science for relevant articles with a time limit of December 2012. The strength of association between the XPC Lys939Gln and Ala499Val polymorphisms and colorectal cancer susceptibility were assessed by odds ratio (OR) with the corresponding 95% confidence interval (95% CI). This meta-analysis including six case-control studies evaluated the associations between the two XPC polymorphisms (Lys939Gln, Ala499Val) and colorectal cancer susceptibility. For XPC Lys939Gln, no obvious associations were found for all genetic models [CC vs AA: OR (95% CI)=1.12 (0.94-1.32); CA vs AA: OR (95% CI)=1.08 (0.94-1.24); the dominant model: OR (95% CI)=1.09 (0.97-1.23); the recessive model: OR (95% CI)=1.07 (0.92-1.25)]. For XPC Ala499Val, no obvious associations were also not found for all genetic models [TT vs CC: OR (95% CI)=0.84 (0.65-1.10); CT vs CC: OR (95% CI)=1.00 (0.86-1.15); the dominant model: OR (95% CI)=0.98 (0.85-1.12); the recessive model: OR (95% CI)=0.87 (0.67-1.12)]. This meta-analysis suggested that both the XPC Lys939Gln and Ala499Val polymorphisms were not risk factors for increasing colorectal cancer.