XPD Lys751Gln and Asp312Asn polymorphisms and gastric cancer susceptibility: a meta-analysis of case-control studies.

BACKGROUND Published data regarding the association between xeroderma pigmentosum group D (XPD) Lys751Gln and Asp312Asn polymorphisms and gastric cancer susceptibility havew been inconclusive. This meta-analysis was therefore performed toobtain a more precise estimation of any relationship. MATERIALS AND METHODS A comprehensive literature search was conducted to identify all case-control studies of Lys751Gln and Asp312Asn polymorphisms and susceptibility to gastric cancer. Summary odds ratios (ORs) and its 95% confidence intervals (95% CIs) were calculated using a random-effects model with the software STATA (version10.0). RESULTS A total of 12 case-control studies including 3,147 cases and 4,736 controls were included. Overall, no significant associations were found in some models (for Lys751Gln: Lys/Gln vs Lys/Lys: OR=1.144, 95% CI=0.851-1.541, Gln/Gln vs Lys/Lys: OR=1.215, 95% CI = 0.740-1.955, dominant model: OR=1.137, 95% CI=0.818-1.582; recessive model: OR=1.123, 95% CI=0.765-1.650; for Asp312Asn: Asp/Asn vs Asp/Asp: OR=1.180, 95% CI=0.646-2.154, dominant model: OR=1.380, 95% CI = 0.812-2.346), but significantly elevated susceptibility was found for Asp312Asn polymorphism in some models (Asn/Asn vs Asp/Asp: OR=2.045, 95% CI=1.254-3.335, recessive model: OR=1.805, 95% CI =1.219-2.672 ), for the additive model, the XPD Lys751Gln and Asp312Asn polymorphisms were not significantly associated with gastric cancer susceptibility. In stratified analyses, significantly elevated susceptibility was found for some models in the Chinese population. CONCLUSION This meta-analysis suggested the XPD Asp312Asn polymorphism might be a potential biomarker of gastric cancer susceptibility in overall population, while both XPD Lys751Gln and Asp312Asn polymorphisms might be risk factors of gastric cancer susceptibility in Chinese.