Purpose: The aim of the present study was to determine the clinical usefulness of nuclear matrix protein 22 (NMP22) as a new urinary marker for the screening of urothelial cancer in patients with microscopic hematuria, especially in comparison with that of voided urine cytology.
Methods: Patients with microscopic hematuria detected at a health examination, who were advised by a consulted urologist to have a cystoscopical examination, were asked to enter this study. Urine samples were collected before cystoscopy and divided into two portions for NMP22 test and voided urine cytology.
Results: Of the 309 patients with microscopic hematuria, 22 cases (7.1%) of urothelial cancer and one case of prostate cancer were detected. For the other cases, 128 (41.4%) were of benign diseases and 158 (51.1%) were designated as having no evidence of disease (NED). The median NMP22 values for urothelial cancer, other diseases and NED were 35.5, 6.7 and 6.0 U/mL, respectively, with 95% confidence intervals of 19.9-228.2, 5.1-9.3 and 5.4-7.2, respectively. The sensitivity of the NMP22 test for urothelial cancer was 90.9% (20/22), whereas the sensitivity of voided urine cytology was only 54.5% (12/22).
Conclusions: The present study indicates that urinary NMP22 is a useful tool for the screening of urothelial cancer in patients with microscopic hematuria.