IL-33 is associated with unfavorable postoperative survival of patients with clear-cell renal cell carcinoma.

The aim of this study was to evaluate the potential prognostic significance of interleukin-33 (IL-33) in patients with clear-cell renal cell carcinoma (ccRCC) after surgical resection. In this retrospective research, we enrolled 203 patients with ccRCC undergoing nephrectomy between 2003 and 2004 in a single institution. We recorded clinicopathologic features, overall survival (OS), and recurrence-free survival (RFS) and assessed IL-33 expression by immunohistochemical staining. On such bases, the correlations between IL-33 expression and clinicopathologic features and prognosis were evaluated. A high expression of IL-33 was significantly associated with advanced TNM stage and Fuhrman grade (p = 0.017 and p < 0.001, respectively) in patients with ccRCC. Moreover, multivariate analysis identified IL-33 as an independent prognostic factor of OS for patients with ccRCC after surgery (hazard ratio = 2.050; 95 % CI 1.223-3.447; p = 0.006). The incorporation of IL-33 into the TNM stage and Fuhrman grade might help to refine individual risk stratification. The IL-33 expression may serve as an independent negative predictor of survival for patients with ccRCC after surgery.