Can the Preoperative Neutrophil-to-Lymphocyte Ratio Significantly Predict the Conditional Survival Probability in Muscle-invasive Bladder Cancer Patients Undergoing Radical Cystectomy?

Abstract

The present study investigated the prognostic value of the preoperative neutrophil-to-lymphocyte ratio (NLR) in bladder cancer patients undergoing radical cystectomy (RC), with a focus on the conditional survival (CS) estimates over time after surgery. We analyzed 385 bladder cancer patients who underwent RC from 1999 to 2012. The patients were classified into 2 groups according to the preoperative NLR (< 2.5 vs.≥ 2.5). The Kaplan-Meier survival analysis was used to calculate the conditional probabilities of cancer-specific survival and overall survival after surgery. Multivariate Cox regression models were used to identify the predictors of 5-year conditional cancer-specific survival and overall survival. Patients with an elevated preoperative NLR (≥2.5) had a greater proportion of advanced-stage tumors (≥ pT3), high-grade tumors, and lymphovascular invasion. Patients with an elevated preoperative NLR (≥ 2.5) had poor CS estimates compared with those with a lower NLR (<2.5) at baseline and 1 year after RC. However, no significant differences in CS probabilities were observed from 2 years after RC onward. In a multivariate Cox regression analysis, the preoperative NLR was identified as a significant predictive factor for 5-year CS at baseline and postoperative 1-year estimation; however, its significance was lost after 2 years postoperatively. Our study results suggest that the dynamic aspect of the NLR should be considered when assessing the prognosis of bladder cancer patients treated with RC over time after the initial estimates, in particular, in patients who have already survived for additional years after surgery.