Variability in the performance of nuclear matrix protein 22 for the detection of bladder cancer.

Purpose: We assessed variability in the diagnostic performance of NMP22® for detecting recurrence and progression in patients with Ta, T1, and/or CIS transitional cell carcinoma of the bladder in a large international cohort.Materials and Methods: NMP22® voided urine levels were measured in 2,871 patients who underwent office cystoscopy for monitoring previous stage Ta, T1 and/or CIS transitional cell carcinoma at 12 participating institutions.Results: Patient characteristics varied considerably among institutions. Overall 1,045 patients (36.4%) had recurrent transitional cell carcinoma (range across institutions 13.6% to 54.3%). Median NMP22® was 5.5 U/ml (range across institutions 2.5 to 18.8). Of the patients 33.5% had grade III tumors (range across institutions 20.6% to 54.0%) and 22.4% had muscle invasive tumors (range across institutions 3.2% to 38.2%). Area under the ROC curve for bladder TCC detection was 0.735 (95% CI 0.715 to 0.755, range across institutions 0.676 to 0.889). The manufacturer rec...