NMP22 is predictive of recurrence in high-risk superficial bladder cancer patients

The nuclear matrix protein 22 (NMP22) assay has been shown to have greater sensitivity for the diagnosis and detection of recurrent urothelial carcinoma of the bladder (UCB) over that of traditional urine cytology. We assessed the use of NMP22 to predict which high-risk superficial UCB patients will have recurrence, progression or disease-related death; we compared these results to standard urine cytology.

One hundred consecutive patients with high-risk superficial UCB were enrolled. During surveillance, urine was collected for cytology and NMP22 testing. Patients were followed for at least 6 months. Retrospective chart review was undertaken to collect data on previous tumour history, tumour characteristics, disease recurrences, progression and death. Kaplan-Meier analyses were performed to determine the significance between NMP22-positive and -negative patients in terms of recurrence-free, progression-free and overall survival. Similar analyses were performed for urine cytology.

From 94 eligible patients, 15 and 79 were NMP22 positive and negative, respectively. The baseline characteristics between the 2 groups were not significantly different in terms of patient characteristics, prior tumour history or intravesical therapies received. Mean recurrence-free survival time was significantly lower in the NMP22 positive group (p = 0.038); however, mean progression-free and overall survival were not significantly different between the 2 groups (p = 0.297 and 0.519, respectively). Urine cytology demonstrated no significant predictive power for disease recurrence, progression or survival.

The nuclear matrix protein 22 assay appears to have predictive value for future tumour recurrences, but not progression or overall survival in patients with high-risk superficial UCB.