Nuclear matrix protein 22 as adjunct to urine cytology and cystoscopy in follow-up of superficial TCC of urinary bladder.

OBJECTIVES: To assess the efficacy of nuclear matrix protein 22 (NMP-22) in the diagnosis of recurrent, superficial bladder cancer and whether it can predict for future recurrence.
METHODS: Patients with diagnosed and treated superficial transitional cell carcinoma urinary bladder (Stage Ta, T1, Tis, Nx, and M0) presenting for surveillance follow-up were prospectively enrolled in this study from February 2004 to August 2005. These patients underwent urine cytology, NMP-22 testing, and cystopanendoscopy on enrollment in the study. For the next year, these patients underwent cystopanendoscopy and cytology at 3-month intervals. The ability of NMP-22 to predict for recurrence was determined using the cystoscopy findings as the reference standard.
RESULTS: A total of 145 patients were included in the study. Of these, 56 had recurrence at enrollment. Of the 56 patients, 48 had positive NMP-22 findings and 22 had positive urine cytology findings. The sensitivity, specificity, positive predictive value, and negative predictive value was 85.7%, 77.5%, 70.6%, and 89.6%, respectively, for NMP-22 alone and 92.9%, 75.3%, 70.3%, and 94.4%, respectively, when the cytology and NMP-22 findings were combined. During the subsequent follow-up of 1 year, 61 recurrences developed in 47 patients. Cox regression analysis showed that those with positive NMP-22 had a 9.57 times greater risk of recurrence during 1 year compared with those with negative NMP-22.
CONCLUSIONS: The results of our study have shown that the addition of NMP-22 testing to cytology increases the sensitivity for recurrence detection in patients with superficial transitional cell bladder cancer. Patients with positive NMP-22 findings developed significantly more recurrences compared with those with negative NMP-22 findings.