Clinical evaluation of nuclear matrix protein 22 (NMP22) in urine as a novel marker for urothelial cancer.

Objectives: This study was undertaken to determine the clinical usefulness of nuclear matrix protein 22 (NMP22) as a novel urine marker for urothelial cancer, particularly, to substitute for voided-urine cytology. Methods: NMP22 values were determined for 280 patients and 20 healthy volunteers by NMP22 Test Kit based on an enzyme-linked immunosorbent assay. Results: When the cut-off value was set at 10 U/ml, the positive rate of urinary NMP22 for urothelial cancer was 80.9% (38/47), whereas that for posttreatment cases and benign diseases was 35.7% (74/207). When urinary NMP22 and voided-urine cytology were compared, the test for urinary NMP22 showed higher sensitivity than cytology in patients with urothelial cancer. When urinary NMP22 values were determined pre- and postoperatively in patients with urothelial cancer, the postoperative value decreased in all patients, and were below the cut-off value in all except one patient. Conclusions: Urinary NMP22 is a useful diagnostic marker as a substitute for voided-urine cytology for the surveillance of urothelial cancer.