Objective: The aim of this study was to predict the discriminating prognostic power of the neutrophil-to-lymphocyte ratio for overall survival in patients with metastatic renal cell carcinoma and to make a new model using the neutrophil-to-lymphocyte ratio.
Methods: From 2007 to 2014, 190 patients with metastatic renal cell carcinoma treated with either systemic immunotherapy or/and vascular endothelial growth factor-targeted therapy were enroled. A multivariable proportional hazard model was developed to investigate the effects of the neutrophil-to-lymphocyte ratio as predictive prognostic factors for overall survival. This new model was incorporated into the current Heng risk model to validate a modified prognostic classification for overall survival.
Results: In multivariable analysis, a high neutrophil-to-lymphocyte ratio [hazard ratio (HR) = 1.65] was a significant independent predictor of shorter overall survival (P = 0.005). Additional neutrophil-to-lymphocyte ratio markers improved the discriminating power of the Heng risk classification, as compared to the existing classification model (C-statistic: 0.7198 vs. 0.6943, P = 0.008). The reclassification of patient prognostic categories using the new model showed a total overall net improvement of 61.4% (P < 0.001).
Conclusion: The neutrophil-to-lymphocyte ratio was a significant prognostic factor of overall survival in metastatic renal cell carcinoma patients treated with systemic therapy. Adding the neutrophil-to-lymphocyte ratio to the Heng model significantly improved the discriminatory power of risk prediction in metastatic renal cell carcinoma.