Objective: To assess the performance of the NMP22® BladderChek® (NMP22-BC) urine test compared with cytological and histological findings for detecting bladder cancer recurrence in patients with a prior history of bladder cancer.
Methods: A prospective study was performed, evaluating a total of 112 urine samples from 67 patients. These samples were obtained prior to cystoscopy and were analyzed with the NMP22-BC. The results were compared against those of voided urine cytology (VUC) and cystoscopy.
Results: Of the 112 samples, there was a total of 27 recurrences (24.1%). The overall sensitivity of NMP22-BC alone was 33%, VUC with malignant or suspicious specimens alone was 37%, and the two methods combined was 46%. The specificity of NMP22-BC alone was 92%, VUC alone was 99%, and both methods combined was 92%. The detection rate of bladder cancer recurrence in high-grade tumors increased from 50% for NMP22-BC alone and 43% for VUC alone, to 64% when both tests were used in combination. The detection rate of recurrence for stages Ta, T2, and CIS was also significantly increased when NMP22-BC and VUC were used in combination. The overall positive and negative predictive values were 68% and 84% respectively. Inclusion of atypia as positive for recurrence (VUC+A) increased the overall sensitivity of cytology to 72% but decreased the specificity to 64%. However, in cases where atypical cytology was confirmed with positive NMP22-BC, the sensitivity of the combination was 46% and specificity was 100%.
Conclusion: NMP22® BladderChek® is a valuable addition to voided urine cytology for detection of high-risk lesions. Our study shows that once atypical cytology is confirmed by NMP22-BC, the specificity is 100%. Furthermore, the sensitivity of this combination is superior to that of malignant or suspicious cytology alone.
Keywords: Bladder cancer, NMP-22, Cytology, Urinary markers
Correspondence: Ravi Munver, Department of Urology, Hackensack University Medical Center, 360 Essex Street, Suite 403, Hackensack, NJ, 07601,