Expression of IL-4 and IL-13 predicts recurrence and survival in localized clear-cell renal cell carcinoma.

Interleukin-4 (IL-4) and IL-13 are anti-inflammatory and immunoregulatory cytokines that can influence cancer-directed immunosurveillance. However, they are not evaluated as biomarkers for ccRCC outcomes. The aim of this study was to investigate the prognostic value of tumor-derived IL-4 and IL-13 in patients with localized ccRCC after surgery. Our study comprised 194 consecutive patients with localized ccRCC undergoing nephrectomy in a single center. Clinical characteristics, recurrence-free survival (RFS) and overall survival (OS) were recorded. We assessed IL-4 and IL-13 expression as continuous variables and dichotomized as low versus high by immunohistochemistry. For associations with RFS and OS, we used the Kaplan-Meier method and Cox regression models. Concordance index was calculated for predictive accuracy. We found that high expression levels of IL-4 and IL-13 were associated with increased recurrence (P < 0.001 and P = 0.006, respectively) and reduced survival (P = 0.001 and P = 0.016, respectively). Furthermore, multivariate analyses confirmed that combination of IL-4 and IL-13 expression (IL-4/IL-13 signature) was an independent prognostic factor for RFS and OS (P = 0.009 and P = 0.016, respectively). When applied to UISS score, IL-4/IL-13 signature improved the predictive accuracy. Notably, this improvement in prediction was mainly observed in patients with low-risk disease. To conclude, IL-4/IL-13 signature is an independent predictor of outcomes in patients with localized ccRCC, and the prognostic value is more prominent among patients with low-risk disease. Evaluation of IL-4 and IL-13 expression provides the opportunity to optimize postsurgical management and develop novel targeted therapies for ccRCC patients.