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

Abstract

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^® 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^® 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^® 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^® 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^® 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.