Introduction and Objectives
Cystoscopy in complement with urinary cytology represents the gold standard for diagnosing and follow up of patients with urinary bladder tumors. Despite the fact that numerous tumor markers have been developed in the past decade, they are still neither routinely used in the clinical practice nor recommended by the EAU guidelines. In our study we have focused on performance of nuclear matrix protein 22 (NMP22) tumor marker test and BladderChek® inoffice test for detection of bladder tumors.
Material and Methods
NMP22 was measured with an ELISA assay (Matritech, Inc, USA). This test is an enzyme immunoassay where antibodies contained recognize the head domain of NuMA, nuclear mitotic protein. NuMA has been shown to be present in malignant tissues at levels more than 10 times higher than in normal tissue. The assay is designed to quantify NMP22 in stabilized voided urine. BladderChek® (Matritech, Inc, USA) in-office test detects elevated NMP22 concentration in 4 drops of voided urine in a panel well incubated for 30 minutes.
NMP22 in urine was measured quantitatively in 94 patients and BladderChek® test was done on 75 urine samples preoperatively or during follow up. Urinary cytology was available for 94 patients and histology report of transurethral resection of bladder lesion was obtained in 40 patients. For prediction of malignant histological result sensitivity and specificity were 18% and 100% respectively for BladderChek® test, 37% and 100% for voided urinary cytology and 44% and 88% for NMP22 at 7.5 kU/l cutoff value,. Area under the curve in the ROC graph for quantitative NMP22 test was 0.73.
Stratified for grade sensitivities of Bladderchek® test, voided urinary cytology and NMP22 quantitative test were 10%,10% and 36% for low grade and 40%, 55% and 42% for high grade tumors respectively. Neither BladderChek® test nor voided urinary cytology found any of papillary urothelial neoplasm of low malignant potential (PUNLMP) tumors, while NMP22 test detected half of them. Stratified for stage in superficial bladder tumors sensitivities of BladderChek® test, voided urinary cytology and NMP22 quantitative test were 9%, 15% and 25% for Ta and 67%, 75% and 78% for T1 tumors respectively.
NMP22 test showed higher sensitivity and lower specificity than voided urinary cytology. Area under the ROC curve for NMP22 test indicates moderate performance of this test. The sensitivity of Bladderchek® test is low. At present time we would not recommend any of the three noninvasive tests, namely voided urinary cytology, NMP22 test or BladderChek® test as a replacement for cystoscopy during diagnosing or follow up of urinary bladder tumors.
© 2009 European Association of Urology. Published by Elsevier Inc. All rights reserved.