XPG gene polymorphisms and cancer susceptibility: evidence from 47 studies

Xeroderma pigmentosum group G (XPG) is a single-strand-specific DNA endonuclease that functions in the nucleotide excision repair pathway. Genetic variations in XPG gene can alter the DNA repair capacity of this enzyme. We evaluated the associations between six single nucleotide polymorphisms (SNPs) in XPG (rs1047768 T> C, rs2296147 T> C, rs2227869 G> C, rs2094258 C> T, rs751402 C> T, and rs873601 G> A) and cancer risk. Forty-seven studies were identified in searches of the PubMed, Scopus, Web of Science, China National Knowledge Infrastructure, and WanFang databases. Crude odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a fixed or random effects model. We found that rs873601 G> A was associated with an increased overall cancer risk (AA vs. GG: OR = 1.14, 95% CI = 1.06-1.24; GA/ AA vs. GG: OR = 1.08, 95% CI = 1.02-1.15; A vs. G: OR = 1.06, 95% CI = 1.02-1.10). In a stratified analysis, rs1047768 T> C was associated with an increased risk of lung cancer, rs2227869 G> C was associated with a decreased risk of cancer in population-based studies, and rs751402 C> T and rs873601 G> A were associated with the risk of gastric cancer. Our data indicate that rs873601 G> A is associated with cancer susceptibility.