Prospective External Validation of a Bladder Cancer Detection Model

Purpose: Few studies have combined clinical prognostic factors with urinary biomarkers into risk profiles that can be used to predict the likelihood of bladder cancer. We previously developed and internally validated a bladder cancer detection nomogram that combines clinical features with the NMP22 (R) BladderChek (R) test. To consider extensive use of the model the nomogram was tested in a prospective cohort of patients who presented with hematuria. Materials and Methods: Patients referred for hematuria evaluation were prospectively enrolled at 3 centers. Each patient underwent complete urological evaluation, including history, examination, cystoscopy, cytology and NMP22. A logistic regression model to predict urothelial bladder carcinoma was also developed to compare the performance of clinical data with and without adding NMP22 and urinary cytology. Results: The study included 381 patients (50.7% women) with a median age of 58 years. Urothelial bladder carcinoma was detected in 23 patients (6%). It was associated with age greater than 65 (11.1% vs 4% of patients, p = 0.012), male gender (10.1% vs 2%, p = 0.003), white ethnicity (9.2% vs 3.1%, p = 0.016), gross hematuria (9.9% vs 2.5%, p = 0.005), positive NMP22 (37% vs 3.7%, p < 0.001) and positive cytology (83.3% vs 3.9%, p < 0.001). Predictive accuracy of the bladder cancer detection nomogram was 80.2%. The calibration plot indicated that the previously published nomogram was well calibrated in patients with a less than 15% predicted probability of urothelial bladder carcinoma. Conclusions: We prospectively validated a highly accurate tool that combines clinical factors and a urinary biomarker to detect bladder cancer. This tool can help prioritize urological referrals for patients with hematuria.