Development of a Nomogram That Predicts Outcomes After Radical Cystectomy for Bladder Cancer Using Data from Siriraj Hospital, Thailand

Abstract

Objective: This study aimed to develop and validate a prognostic nomogram to estimate individualized overall survival (OS) for bladder cancer patients in Thailand undergoing radical cystectomy (RC), using data from Siriraj Hospital. Materials and Methods: We retrospectively analyzed a cohort of 304 bladder cancer patients who underwent RC at Siriraj Hospital between 2012 and 2023. The patients were randomly allocated to the training (80%) and testing (20%) cohorts. Cox regression analyses were employed to identify predictors of OS from a range of clinical, pathological, and treatment-related variables. A prognostic nomogram was subsequently constructed and its performance was validated using the concordance index and the area under the receiver operating characteristic curve (AUC). Results: The median patient age was 68 years and the majority of patients presented with muscle-invasive disease. The median duration of follow-up was 61 months, with a median overall survival of 51 months. Multivariate analysis identified five independent predictors of OS: age, preoperative glomerular filtration rate, type of urinary diversion, pathological N stage, and presence of lymphovascular invasion. The nomogram demonstrated strong predictive performance, with AUC values of 86.6% at 12 months, 84.0% at 36 months, and 76.6% at 60 months. Conclusion: We have developed and validated a prognostic nomogram tailored for Thai bladder cancer patients undergoing RC. This tool provides individualized survival estimates and may be a valuable aid in patient counseling, risk stratification, and formulation of postoperative management strategies. Future multicenter validation and integration of molecular markers will enhance the clinical utility of the prognostic nomogram.