Usefulness of urinary nuclear matrix protein 22 (NMP22) as a marker for transitional cell carcinoma of the bladder - Evaluation of cut-off value in primary and recurrent bladder cancer in comparison with voided urine cytology

We studied the clinical usefulness of the nuclear matrix protein 22 (NMP22) as a urine marker of bladder cancer in comparison with voided-urine cytology (VUC). Urinary NMP22 and VUC were determined in 71 patients with bladder cancer (48 patients with primary cancer and 23 with recurrent cancer), and in 87 patients without urothelial cancer. When the cut-off value was set at 12 U/ml, the sensitivity of urinary NMP and VUC was 56.3% and 56.3% in overall bladder cancer, 64.6% and 60.4% in primary cancer, and 39.1% and 47.8% in recurrent cancer, respectively. When the cut-off value was set at 6.3 U/ml for primary cancer and 5.2 U/ml for recurrent cancer, the sensitivity of urinary NMP improved to 81.3% and 78.3%, respectively, without any significant decrease in specificity. These sensitivities using new cut-off values were significantly higher than those of VUC. These data indicate that urinary NMP22 is a useful urinary marker for the monitoring of recurrent bladder cancer as well as for the screening of primary bladder cancer.