Development and external validation of a nomogram to predict high-grade papillary bladder cancer before first-time transurethral resection of the bladder tumor

Background The aim of this study was to identify the clinical predictors related to the risk of high-grade papillary bladder cancer before first-time transurethral resection of a bladder tumor (TUR-Bt), and to develop and validate a nomogram predicting the risk of high-grade papillary bladder cancer.