Interleukin-33 Expression does not Correlate with Survival of Gastric Cancer Patients

The aim of the study was to investigate IL-33 expression in gastric cancer (GC) and its association with the clinical characteristics and the prognosis. IL-33 protein in tumor and corresponding adjacent tissues were detected by immunohistochemistry in 179 GC patients and clinical features plus prognostic value were analyzed via Pearson's chi-square test and Kaplan-Meier test in Cox proportional hazards model, respectively. IL-33 protein levels were significantly lower in tumor tissues than adjacent tissues (29.05% vs. 78.77%, χ ²  = 89.05, P < 0.001). The positive rate of IL-33 in the ulcerative type group was the lowest among all groups (P < 0.05). IL-33 levels were correlated with age (P = 0.025) and invasion depth (P = 0.030) while not significantly associated with the overall survival of GC patients. IL-33 expression is associated with age and invasive depth of GC patients but not an independent risk factor of prognosis.