Association Between IL18-607C/A and -137G/C Polymorphisms and Susceptibility to Non-small Cell Lung Cancer in a Chinese Population

Lung cancer is one of the main causes of cancer-related mortality in males and females worldwide. A pleiotropic effect has been observed in the interleukin 18 gene (IL18); its effects include the activation of natural killer cell cytotoxicity and the promotion of the Th1 immune response through the alteration of the expression of interferon-γ and TNF-α in humans. IL18 is therefore involved in the elimination of tumor cells in the human body. We recruited 357 patients with non-small cell lung cancer (NSCLC) and 414 controls to evaluate the correlation between two genetic variations (IL18-607C/A and IL18-137G/C) and the pathogenesis of NSCLC. We used polymerase chain reaction-restriction fragment length polymorphism to genotype IL18-607C/A and IL18-137G/C. Statistical analysis revealed that individuals harboring the AA genotype of IL18-607C/A had an increased risk of NSCLC compared to those harboring the CC genotype (OR = 2.20, 95%CI = 1.30-3.74). Individuals expressing the A allele of IL18-607C/A had an elevated risk of developing NSCLC compared to those expressing the C allele (OR = 1.31, 95%CI = 1.06-1.62). In summary, our analysis shows that the IL18-607C/A genetic variation is related to the risk of NSCLC, whereas the IL18-137G/C variation is not. Therefore, the IL18-607C/A variation is related to the pathogenesis of NSCLC in the Chinese population studied.