Contribution of Interleukin-4 Genotypes to Lung Cancer Risk in Taiwan

Lung cancer is the leading cause of cancer-related death worldwide. Interleukin-4 (IL-4) is a typical pleiotropic T helper 2 cytokine involved in immunology during carcinogenesis. The present study aimed at evaluating the contribution of IL-4 promoter T-1099G (rs2243248), C-589T (rs2243250), C-33T (rs2070874) genetic polymorphisms to the risk of lung cancer in Taiwan. The contributions of the promoter IL-4 polymorphic genotypes to lung cancer risk were investigated in 358 lung cancer patients and 716 age- and gender-matched healthy controls. In addition, the interaction between IL-4 and individual smoking status was also evaluated. The percentages of CC, CT and TT for IL-4 C-589T genotypes were differentially represented as 69.0%, 26.5% and 4.5% in the lung-cancer patient group and 61.3%, 30.4% and 8.3% in the non-cancer control group, respectively (p=0.0156). The TT genotype carriers were of lower risk for lung cancer (odds ratio (OR)=0.48, 95% confidence interval (CI)=0.27-0.86, p=0.0106) than the CC genotype carriers. We also analyzed the allelic frequency distributions and the results showed that the T allele of IL-4 C-589T conducted a protective effect on lung cancer susceptibility (p=0.0022). On the contrary, there was no difference in the distribution of genotypic or allelic frequencies among patients and controls for the IL-4 promoter T-1099G and C-33T. The TT genotype of IL-4 C-589T compared to the CC wild-type genotype may have a protective effect on lung cancer risk in Taiwan and may serve as an early detection and prediction marker.