Performance of nuclear matrix protein 22 urine marker and voided urine cytology in the detection of urinary bladder tumors

Background: Cystoscopy with urinary cytology is the gold standard for the diagnosis and follow-up of patients with tumors of the urinary bladder. The aim of the study was to evaluate the performance of the nuclear matrix protein 22 (NMP22) tumor marker test, BladderChek (R) point-of-care test and voided urinary cytology for the detection and follow-up of bladder tumors. Methods: NMP22 was measured using an ELISA assay in stabilized voided urine and using the BladderChek (R) test. Voided urinary cytology was performed on urine samples. Results were compared to cystoscopic findings and histopathological examination results after transurethral resection of the bladder lesion. Results: For the prediction of malignant histopathological result, sensitivity and specificity were 45.2% and 75.0%, respectively, for NMP22 at a cut-off of 7.5 kU/L, 17.7% and 100% for the BladderChek (R) test and 37.0% and 100% for voided urine cytology. For the prediction of suspicious or positive cystoscopic finding, sensitivity and specificity were 40.4% and 72.1%, respectively, for NMP22 at a cut-off of 7.5 kU/L, 14.8% and 93.8% for the BladderChek (R) test and 26.8% and 98.1% for voided urine cytology. Conclusions: The NMP22 quantitative test showed higher sensitivity and lower specificity compared with voided urine cytology, whereas the sensitivity of the BladderChek (R) test was low. We could not recommend any of the three non-invasive tests as a replacement for cystoscopy for the diagnosis or follow-up of urinary bladder tumors.