IL-32 expression is an independent prognostic marker for gastric cancer

A strong link between inflammation and gastrointestinal cancer has been demonstrated. Interleukin (IL)-32 is a recently described pro-inflammatory cytokine characterized by the induction of nuclear factor kappa B (NF-κB) activation. We investigated whether IL-32 expression has clinical significance in gastric cancer. A total of 182 gastric cancer patients who received curative gastrectomy were enrolled in our study. IL-32 expression was detected by immunohistochemistry, and the correlation between clinicopathological features and IL-32 expression was analyzed. Tumor depth and lymph node metastases developed more frequently in IL-32-positive gastric cancer patients than those who were negative for IL-32 expression (p < 0.01). Lymphatic- and venous invasion in the IL-32-positive group were more severe than in cancer cells lacking IL-32 expression (p < 0.05). Multivariate analysis demonstrated that IL-32 is one of the prognostic markers (p < 0.03) for gastric cancer, in addition to nodal involvement and tumor depth. IL-32 positivity significantly affected clinicopathological factors. Thus, IL-32 expression in gastric cancer may serve as a preferential metastatic condition that allows cells to escape host antitumor immunity. Pro-inflammatory cytokines induce immunosuppression in a paracrine manner, thereby facilitating the metastasis of tumor cells.