Polymorphisms of excision repair gene XPD Lys751Gln and hOGG1 Ser326Cys might not be associated with hepatocellular carcinoma risk: a meta-analysis.

The xeroderma pigmentosum group D (XPD) and human 8-oxoguanine glycosylase 1 (hOGG1) genes have been suggested to play an important role in the pathogenesis of hepatocellular carcinoma (HCC). However, the results have been inconsistent. In this study, we performed a meta-analysis to clarify the associations of polymorphisms of XPD and hOGG1 genes with HCC risk. Published literature from PubMed, EMBASE, and Chinese National Knowledge Infrastructure were retrieved. Pooled odds ratio (OR) with 95 % confidence interval (CI) was calculated using a fixed- or random-effects model. Seven studies (1,955 HCC cases and 2,023 controls) for XPD Lys751Gln polymorphism and six studies (1,470 HCC cases and 1,541 controls) for hOGG1 Ser326Cys polymorphism were included in the final meta-analysis. For XPD Lys751Gln polymorphism, no significant association was found under all genetic models (Gln/Gln vs Lys/Lys OR = 1.09, 95 % CI = 0.28-4.18; Gln/Lys vs Lys/Lys OR = 1.41, 95 % CI = 0.81-2.44; dominant model OR = 1.40, 95 % CI = 0.77-2.57; recessive model OR = 1.02, 95 % CI = 0.33-3.23). For hOGG1 Ser326Cys polymorphism, there was a significant association of this polymorphism with HCC risk under heterogeneous codominant model (OR = 1.38, 95 % CI = 1.01-1.88) and dominant model (OR = 1.57, 95 % CI = 1.14-2.16). The sensitivity analysis indicated that the significant association between hOGG1 Ser326Cys polymorphism and HCC risk was not robust. The present meta-analysis has limited evidence to support the association of XPD Lys751Gln and hOGG1 Ser326Cys polymorphisms with HCC risk. Further, large-scale studies with the consideration for gene-gene/gene-environment interactions should be conducted to investigate the association.