XPD Polymorphisms and Risk of Hepatocellular Carcinoma and Gastric Cancer: A Meta-Analysis

BACKGROUND: Cancer is associated with genetic variants of DNA repair genes that alter DNA repair capacity. The aim of this meta-analysis was to evaluate the relations between the rs13181 and rs1799793 XPD gene polymorphisms and risk for hepatocellular carcinoma (HCC) and gastric cancer. METHODS: Relevant publications were systematically sought from Web of Science, Pubmed, and China Academic Journals Full-text Database. The selection of eligible studies was performed by 2 independent authors. A total of 32 case-control studies were included. Meta-analyses were undertaken in all study participants and each ethnic group. RESULTS: The risk of HCC was significantly increased with the XPD rs13181 G allele (P = 0.028, pooled odds ratio (OR) = 1.36, 95% confidence interval (CI) = 1.03-1.80) in all study participants. A subgroup analysis by ethnicity showed that the association was significant in Chinese (P = 0.009, pooled OR = 1.49, 95% CI = 1.11-2.02), but not in Caucasians (P = 0.619, pooled OR = 1.17, 95% CI = 0.64-2.13). Meta-analysis of the XPD rs1799793 polymorphism and HCC showed an association between its variant T allele and increased HCC risk in all study participants (P = 0.017, pooled OR = 1.23, 95% CI = 1.04-1.46, all Chinese). Our results showed no associations between the XPD rs13181 G allele and rs1799793 T allele and gastric cancer risk (rs13181: P = 0.298, pooled OR = 1.10, 95% CI = 0.92-1.31; rs1799793: P = 0.068, pooled OR = 1.31, 95% CI = 0.98-1.74). CONCLUSIONS: This meta-analysis demonstrated that the XPD rs13181 G allele and rs1799793 T allele have significant associations with HCC and may be risk factors for HCC in the Chinese population. Current evidence indicated that they are not related to gastric cancer risk.