Introduction and Objectives
To prospectively evaluate the clinical role of urinary NMP22 as a marker for transitional cell carcinoma of the urinary bladder in surveillance settings.
Material and Methods
Single voided specimens were obtained from 25 consecutive patients who presented for cystoscopy. All of these patients presented with previously treated superficial bladder TCC with of without haematuria or irritative symptoms for regular follow up. The urine sample was used for urine microscopy, and for measuring NMP22 levels in 12 to 36 months of follow up.
Bladder tumours were found in 5 of 25 (20%) patients on surveillance. The NMP22 levels were significantly lower in patients with lower stage (Ta vs. T1–3), low grade (G1, G2 vs. G3, CIS) and papillary morphology. The optimum threshold for NMP22 was 10.0 U/ml, providing a sensitivity, specificity, positive predictive value and negative predictive value of 40.0, 85, 38.5 and 88.0% respectively. Sensitivity and specificity were better in patients being on surveillance for a longe period and with sterile urine samples
Urinary NMP22 levels are significantly higher in patients with bladder tumour than in those negative for tumours, and test predictability improves with increasing stage and grade. The overall sensitivity for urinary NMP22 is similar to cystoscopy but can not replace it. With cystoscopy together gives almost 100% accurate diagnosis of relapsing bladder TCC. Our study suggests that the clinical role of urinary NMP22 as a diagnostic marker can be at best supportive only, with potential advantage in follow up after resection of high risk bladder TCC (T1G3, CIS).
© 2009 European Association of Urology. Published by Elsevier Inc. All rights reserved.