Background: A recent genome-wide association study (GWAS) has posed STAT4 as a promising susceptibility gene for hepatocellular carcinoma (HCC). However, the most significant variant in this GWAS, rs7574865, yielded inconsistent results.
Objective: This study, in a Southern Chinese population, was aimed to clarify the roles in HCC incidence of the rs7574865 and other two potentially functional variants, rs897200 and rs1031507 in STAT4.
Methods: This study enrolled 631 new HCC cases and 631 cancer-free controls. The genetic association was estimated using the multivariate logistic regression model. The pairwise gene-environment interactions were assessed using the multiplicative term in regression model and the "Delta" method for the additive scale.
Results: In the multivariate analysis, the rs7574865 TT genotype conferred a decreased risk of HCC compared to the GG genotype (adjusted OR = 0.62, 95%CI = 0.38∼0.99). The significant association of rs7574865 was also observed under the additive genetic model, with an adjusted OR of 0.81 (95%CI = 0.65∼0.99). Nevertheless, other two variants alone showed no significant association, as well as the haplotypes and genetic risk scores. Further analysis indicated a potential interaction between the rs897200 and alcohol drinking (P= 0.048 and 0.072 for additive and multiplicative interactions, respectively). Drinkers with the rs897200 CT+CC genotypes presented an increased disease-risk, as compared with non-drinkers carrying the TT genotype (adjusted OR = 1.68, 95%CI = 1.11∼2.54).
Conclusions: The variant in STAT4, rs7574865, serves as a potential marker for predicting incidence of HCC. The rs897200 variant possibly interplays with alcohol drinking to alter HCC risk in the Southern Chinese, but warrants further investigation.
Keywords: Hepatocellular carcinoma (HCC); gene-environment interaction; genetic variant; genotype; signal transducer and activator of transcription 4 (STAT4).