Serum and tissue levels of interleukin-12 and interleukin-18 in intestinal type gastric cancer

Introduction: Interleukin-12 (IL-12) and interleukin-18 (IL-18) have implication in tumor's immunology. Aim of the study was to evaluate the concentrations of IL-12 and IL-18 in serum and tumor tissues of patients with intestinal type gastric cancer (GC). The relationship between the levels of these cytokines and clinicopathological parameters was investigated. Material and methods: IL-12 and IL-18 concentrations were measured by ELISA tests in serum from 57 patients with GC and 38 healthy subjects, and in tissue homogenates - from 29 operated GC patients. Results: Serum levels of IL-12 and IL-18 were significantly higher in GC patients than in control (p<0.001 for both). In GC patients concentrations of serum IL-12 were negatively associated with cancer stage (p=0.002) and primary tumor progression (p=0.048). Diagnostic sensitivity of IL-12 was higher (72%) than of IL-18 (51%). The receiver operating characteristics (ROC) demonstrated that the area under the ROC curve (AUC) for IL-12 was larger than for IL-18. Concentrations of IL-12 and IL-18 were higher in the tumor tissues than in normal control tissues, but they were not significant. Conclusions: IL-12 and IL-18 are involved in the development of intestinal type gastric cancer. The significant increase of serum IL-12 concentration in the early stage of GC may support the proposed role of IL-12 in host antitumor activity.