The value of the NMP22 test for superficial bladder cancer diagnosis and follow-up

Objective: In this study, we investigated the efficacy of nuclear matrix protein 22 (NMP22) in the diagnosis and surveillance of bladder cancer.

Material and methods: Patients with a complaint of hematuria or who required cystoscopic control of proven bladder cancer were prospectively enrolled in this study. A routine cytologic examination and NMP22 test were performed on the voided urine sample that was provided before the cystoscopy. The patients who had been diagnosed with bladder cancer were categorized according to stage, grade, number, measure and risk, and the diagnostic performance of the NMP22 test and the cytology test, alone or in combination, were evaluated separately using ROC curves in the diagnosis and surveillance groups.

Results: There were 87 patients (of the 136 total patients) who were investigated because of hematuria. The sensitivity, specificity, positive predictive value, negative predictive value and positive likelihood ratio (LR+) of the NMP22 test were 70%, 80%, 68%, 81% and 3.42, respectively. The sensitivity, specificity, positive predictive value, negative predictive value and positive likelihood ratio (LR+) of the cytology examination were 27%, 96%, 82%, 68% and 7.36, respectively. There were 49 patients in the group that had been diagnosed with bladder cancer. The sensitivity, specificity, positive predictive value, negative predictive value and positive likelihood ratio (LR+) of the NMP22 test in these patients were 33%, 76%, 31%, 78% and 1.37, respectively. The sensitivity, specificity, positive predictive value, negative predictive value and positive likelihood ratio (LR+) of the cytology examination were 25%, 97%, 75%, 80% and 9.25, respectively.

Conclusion: The NMP22 test can be used as an adjunctive tool for the detection of bladder cancer, but its diagnostic performance is limited in surveillance when used alone or in combination with a cytology examination.