title: Lack of association between the interleukin 6 gene -174G>C polymorphism and colorectal cancer: evidence from a meta-analysis.
abstract: Interleukin 6 (IL6) is a pleiotropic cytokine involved in physiological processes and in a variety of human malignancies. It is thus a logical candidate for being a causative factor underlying colorectal cancer (CRC). The association between the IL6 -174G>C polymorphism and CRC has been widely evaluated; yet, there is a lack of agreement between studies on the role of this polymorphism in CRC. We performed a meta-analysis to evaluate this association signal. Articles published before May 10, 2012 were included in the meta-analysis. A total of 11 populations incorporating 6481 cases and 7935 controls were included in our analysis. A random-effect model was applied irrespective of between-study heterogeneity. Data and study quality were assessed in duplicate. Overall, the association of the -174G>C polymorphism with CRC was not significant in an allelic comparison model [odds ratio (OR) = 0.99; 95% confidence interval (95%CI) = 0.90-1.09; P = 0.827], a homozygote model (OR = 0.98; 95%CI = 0.83-1.15; P = 0.805), a dominant model (OR = 0.99; 95%CI = 0.87-1.13; P = 0.906), or a recessive model (OR = 0.97; 95%CI = 0.88-1.08; P = 0.610). Furthermore, the analyses of subgroups created based on common study design, genotyping methods, and ethnicity failed to find a significant association of this polymorphism with CRC. Therefore, our results collectively suggest that the IL6 -174G>C polymorphism might not be a potential candidate for CRC risk.
authors.affiliation: Department of Gastroenterology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: J J
authors.initials: JJ
authors.lastname: Hu
authors.forename: Z T
authors.initials: ZT
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Zhong
mesh_terms: D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000208:ethnology / Q000235:genetics*; D005799:Genes, Dominant; D005808:Genes, Recessive; D056726:Genetic Association Studies; D006720:Homozygote; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D008957:Models, Genetic; D020641:Polymorphism, Single Nucleotide; D011153:Population / Q000235:genetics; D044465:White People
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6