Association between STAT3 polymorphisms and cancer risk: a meta-analysis

Five polymorphisms, rs2293152, rs4796793, rs12949918, rs6503695, rs744166, in the STAT3 gene have been implicated in susceptibility to cancer, but the results were inconclusive. The aim of this meta-analysis is to investigate the association between the five polymorphisms and cancer risk. All eligible case–control studies published up to March 2015 were identified by searching PubMed, Web of Science, Wanfang, VIP, and CNKI. Effect sizes of odds ratio (OR) and 95 % confidence interval (95 % CI) were calculated by using a fixed- or random-effect model. A total of 15 articles were included. Overall, a significantly decreased risk was found for rs12949918 polymorphism (dominant model: OR = 0.83, 95 % CI: 0.75–0.91, recessive model: OR = 0.77, 95 % CI: 0.68–0.87, TC vs. TT: OR = 0.87, 95 % CI: 0.79–0.96, CC vs. TT: OR = 0.71, 95 % CI: 0.62–0.81), and for rs744166 polymorphism (recessive model: OR = 0.75, 95 % CI: 0.58–0.98; GG vs. AA: OR = 0.68, 95 % CI: 0.51–0.90), while there was no significant association for other three polymorphisms under all genetic models. In subgroup analysis by ethnicity, for rs12949918 polymorphism, similar results were detected among Caucasians, similarly, a significant decreased risk was observed in Asians under dominant and CC vs. TT model; for rs2293152 polymorphism, significant association was detected among Asians under recessive model. This meta-analysis suggests that the STAT3 rs12949918 and rs744166 polymorphisms, but not other three polymorphisms, may be an important protective factor for cancer.