Clinical application of NMP22 in the management of transitional cell carcinoma of the bladder

The combination of a noninvasive, quantitative immunoassay, NMP22, with voided urinary cytology prior to cystoscopy was evaluated in patients with urothelial transitional cell carcinoma. Fifty-six patients with a history of transitional cell carcinoma were evaluated. Voided urine was obtained for NMP22 and cytology prior to cystoscopy. One hundred and twenty-three NMP22 assays, 124 cytologies, and 124 cystoscopies were performed. The type of anesthesia used for cystoscopic evaluation was determined by the NMP22 value in 30 patients. Cystoscopy results were considered positive on biopsy-confirmed malignancy. The reference value used for NMP22 was 10.0 U/ml. NMP22, cytology, and the combination of NMP22 and cytology were compared to cystoscopy and to pathologic grading and staging. Thirty-four recurrent transitional cell carcinoma episodes occurred; 22 were low-grade (I-II), and 12 were high-grade (III-IV). Twenty-seven were stage Ta; four were T1; and three were T3b or 4. Within this group, NMP22 detected low- and high-grade tumors equally, as compared to cytology, which was sensitive only to high-grade tumors. Nineteen patients were NMP22-negative and underwent cystoscopy under topical anesthesia; 17 were tumor-free. Eleven patients were NMP22-positive and had anesthesia, and all had visible lesions, which were subjected to biopsy and were resected. Six lesions were tumors, five were inflammatory. Overall sensitivity of combined NMP22 and cytology was 70%; specificity was 72%; positive predictive value was 54%; and negative predictive value was 77%. An accurate assessment of the risk of a bladder cancer can be obtained with NMP22, cytology, and cystoscopy in patients with a history of bladder cancer. NMP22 values can be used to determine the level of anesthesia for cystoscopy in patients with a history of bladder cancer.