Association of IL-6 polymorphisms with hepatocellular carcinoma risk: evidences from a meta-analysis

The associations between IL-6 gene single nucleotide polymorphisms (SNPs) and risk of hepatocellular carcinoma (HCC) are controversial. We performed a meta-analysis to provide more credible evidence. We searched for relevant studies published up to 2013 by performing an efficient searching strategy. Odds ratios (OR) with 95% confidence interval (95% CI) was used to estimate the strength of the associations between IL-6 polymorphisms and HCC risk. We identified eight case-control studies involving 1,448 HCC cases and 3,160 controls. Our estimation specifically focused on two SNPs of the IL-6 gene, -174 G/C and -572 G/C. The combined results showed that association between IL-6-174 G/C polymorphism and risk of HCC was significant under additive model (CC vs. GG: OR 0.36; 95% CI, 0.16, 0.85) and recessive model (GG+CG vs. CC: OR 2.82; 95% CI 1.26, 6.28). However, the IL-6-572 G/C polymorphism was not associated with HCC risk. In conclusion, IL-6-174 G/C, but not -572 G/C polymorphism could be a candidate for susceptibility to HCC. However, the results should be cautiously interpreted due to the limited number of the included studies.