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

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. A retrospective clinical study of consecutive patients who underwent first-time TUR-Bt for papillary bladder cancer was performed. Medical records were reviewed uniformly, and the following data were collected: age, sex, episodes of urinary symptoms, tumor size, number of tumors, location of the largest tumor (lateral walls, base, posterior wall, dome, and anterior wall), tumor appearance (papillary or non-papillary, pedunculated or sessile), and urinary cytology. Data from 254 patients (Group A) were used for the development of a nomogram, while data from 170 patients (Group B) were used for its external validation. High-grade papillary bladder cancer was pathologically diagnosed in 51.6 and 74.6% of Group A and Group B patients, respectively. Based on univariable analyses in Group A, macrohematuria, tumor size, multiple tumors, appearance, and positive urinary cytology were selected as variables to incorporate into a nomogram. The AUC value was 0.81 for the internal validation (Group A), and 0.78 for the external validation (Group B). This novel nomogram can predict high-grade papillary bladder cancer accurately. The present nomogram can help clinicians calculate the probability in patients with bladder cancer before TUR-Bt and decide on earlier intervention and priorities for the treatment of patients diagnosed with bladder cancer.