Significant association of interleukin-10 genotypes and oral cancer susceptibility in Taiwan

Interleukin-10 (IL10) is an immunosuppressive cytokine which may facilitate carcinogenesis by downregulating interferon-gamma production and supporting tumor escape from the immune response. Polymorphisms within the promoter of IL10 gene may not only contribute to differential IL10 expression levels among individuals but also to oral cancer susceptibility. In this hospital-based study, the association of IL10 A-1082G (rs1800896), T-819C (rs3021097), and A-592C (rs1800872) polymorphisms with oral cancer risk were examined. A total of 788 cases with oral cancer risk and 956 controls were genotypes and analyzed by polymerase chain reaction and restriction fragment length polymorphism. The results showed that there were significant differential distributions among oral cancer cases and controls in the genotypic (p= 6.29×10^-11) and allelic (p=2.80×10^-13) frequencies of IL10 A-1082G. Individuals who carried the AG or GG genotype for IL10 A-1082G had a 1.90- and 3.27-fold higher risk, respectively, of developing nasopharyngeal carcinoma compared to those who carried AA genotype (95% confidence interval=1.51-2.39 and 1.95-5.47). None of the other two polymorphisms investigated appear to affect cancer risk. In gene-lifestyle interaction analysis, we provide first evidence showing of an obvious joint effect of IL10 A-1082G genotype with individual smoking and areca chewing habits on nasopharyngeal carcinoma risk. The AG and GG genotypes of IL10 A-1082G, together with smoking and areca chewing habits, synergistically contribute to individual susceptibility for oral cancer.