Evaluation of urinary NMP22 (nuclear matrix protein 22) as a diagnostic marker for urothelial cancer--NMP22 as a urinary marker for surveillance of bladder cancer. NMP22 Study Group]

This study was undertaken to determine the clinical usefulness of NMP22 (Nuclear Matrix Protein 22) as a urinary marker for the surveillance of bladder cancer, especially in comparison with that of voided urine cytology. Urinary NMP22 values were determined for 144 patients with histologically diagnosed bladder cancer, 65 patients with other urological cancers, and 171 healthy volunteers by use of a UNMP22 Test kit, which is based on an enzyme-linked immunosorbent assay. All bladder cancer patients were evaluated for urinary NMP22 values and voided urine cytology simultaneously from the same urine samples. Based on the data from the bladder cancer patients and the healthy volunteers, the cut-off value was set at 12 U/ml. The median urinary NMP22 value for the bladder cancer patients was 17.8 U/ml (95% CI: 13.1-29.0). The sensitivities of urinary NMP22 and voided urine cytology were 61.1% (88/144) and 33.8% (48/144), respectively, a significant difference (p < 0.00001). Multivariate analysis revealed that tumor size affected the urinary NMP22 values. The positive rate by tumor size was 42.3%, 59.1%, and 85.0% for tumors of < 10 mm, 10-30 mm, and > 30 mm, respectively. Urinary NMP22 values decreased postoperatively in 82.9% of the patients. The median NMP22 values for prostate cancer and renal cancer were 4.4 U/ml (95% CI: 2.2-6.7) and 6.2 U/ml (95% CI: 3.6-12.5). The positive rates were 24.2% and 31.3%, respectively, both of which were significantly lower than for bladder cancer. Our multicenter study indicates that urinary NMP22 test is more sensitive than voided urine cytology test for the surveillance of bladder cancer.