External validation and comparison of nomograms for prediction of long-term disease recurrence and survival for bladder cancer patients who undergo radical cystectomy

BACKGROUND: This study aimed to compare existing nomograms and identify which models best predict long-term survival outcomes, namely disease-free survival (DFS) or recurrence-free survival (RFS), and cancer-specific survival (CSS), in patients undergoing radical cystectomy (RC) for bladder cancer (BC). METHODS: Six nomograms (three for DFS, three for CSS) were selected from 20 studies and evaluated using data from 730 RC patients treated at University Hospitals Leuven. Discriminatory performance was assessed using area under the curve (AUC) of receiver operating characteristics (ROC) curve, along with sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy. Calibration was analyzed using the Hosmer-Lemeshow (HL) test and calibration plots, while clinical utility was assessed through decision curve analysis (DCA). Statistical significance was set at P