The association of TNF-308 (G/A) gene polymorphisms and hepatocellular carcinoma risk: a meta-analysis

OBJECTIVE Many studies have examined the association between the TNF-308 G/A polymorphism gene polymorphisms and hepatocellular carcinoma risk in various populations, but their results have been inconsistent. To assess this relationship more precisely, a meta-analysis was performed. METHODS The PubMed and CNKI (China National Knowledge Infrastructure) database was searched for case-control studies. Odds ratios (OR) with 95% CIs were used to determine the strength of association between the TNF-308 G/A polymorphisms and HCC risk. The pooled ORs for the risk associated with the TNF-308 G/A genotype, the A carriers (A/G + A/A) vs. the wild-type homozygotes (G/G), A/A vs. G/G were calculated, respectively. Subgroup analyses were done by ethnicity and smoking status. Heterogeneity assumptions were assessed by chi-square-based Q-test. RESULTS Ultimately, 21 studies, comprising 2,923 hepatocellular carcinoma cases and 4,323 controls were included. Overall, the A carriers (G/A + A/A) vs. the wild-type homozygotes (G/G), the pooled OR was 1.05 (95% CI, 0.93-1.19; P=0.000 for heterogeneity), for A/A vs. G/G the pooled OR was 1.07 (95% CI, 0.95-1.21; P=0.007 for heterogeneity). In the stratified analysis by ethnicity, the significantly risks were found among non-Asians. However, for Asians, significantly risks were not found. CONCLUSIONS The TNF-308 G/A polymorphisms are not associated with hepatocellular carcinoma risk among Asians, but for non-Asians.