Combined effects of six cytokine gene polymorphisms and SNP-SNP interactions on hepatocellular carcinoma risk in Southern Guangxi, China.

Cytokine gene single nucleotide polymorphisms (SNPs) are involved in the genesis and progression of hepatocellular carcinoma (HCC). We hypothesized that combined effects of cytokine gene SNPs and SNP-SNP interactions are associated with HCC risk. Six SNPs in cytokine genes (IL-2, IFN-γ, IL-1β, IL-6, and IL-10) were genotyped in a study of 720 Chinese HCC cases and 784 cancer-free controls. Although none of these SNPs individually had a significant effect on the risk of HCC, we found that the combined effects of these six SNPs may contribute to HCC risk (OR=1.821, 95% CI=1.078-3.075). This risk was pronounced among smokers, drinkers, and hepatitis B virus carriers. A SNP-SNP interaction between IL-2-330 and IFN-γ-1615 was associated with an increased HCC risk (OR=1.078, 95% CI=1.022-1.136). In conclusion, combined effects of SNPs and SNP-SNP interactions in cytokine genes may contribute to HCC risk.