Association of the interleukin-18 receptor 1 and interleukin-18 receptor accessory protein polymorphisms with the risk of esophageal cancer

Esophageal cancer is the fourth leading cause of cancer-associated fatalities and the fourth most commonly diagnosed cancer. In addition to environmental risk factors, genetic factors may have a significant role in esophageal cancer carcinogenesis. A hospital-based case-control study was conducted to evaluate the genetic effects of functional single-nucleotide polymorphisms in the interleukin-18 (IL-18), IL-18 receptor 1 protein (IL-18R1), IL-18 receptor accessory protein (IL-18RAP) and IL-28B on the development of esophageal cancer. In total, 380 esophageal squamous cell carcinoma (ESCC) cases and 380 controls were recruited for the present study. The IL-18 rs360719 A> G, IL-18R1 rs13015714 G> T, IL-18RAP rs917997 C> T and IL-28B rs8099917 T> G genotypes were determined. No association was observed between the IL-18R1 rs13015714 G> T, IL-18RAP rs917997 C> T and IL-28B rs8099917 T> G polymorphisms and the risk of ESCC. However, in stratification analyses, a significantly decreased risk of ESCC associated with the IL-18R1 rs13015714 G> T polymorphism and a significantly increased risk of ESCC associated with the IL-18RAP rs917997 C> T polymorphism was evident among male patients and patients who smoked or consumed alcohol. These findings highlighted that functional polymorphisms IL-18R1 rs13015714 G> T and IL-18RAP rs917997 C> T may contribute to ESCC susceptibility among these subgroups. However, the present results were obtained with a limited sample size and further epidemiological studies are warranted to clarify the role of IL-18R1 and IL-18RAP variants in the development of ESCC.