Comparison of the Efficacy of Urine Cytology, Nuclear Matrix Protein 22 (NMP22), and Fluorescence in Situ Hybridization (FISH) for the Diagnosis of Bladder Cancer

Abstract

Purpose: We compared the efficacy of urine cytology, nuclear matrix protein 22 (NMP22), and fluorescence in situ hybridization (FISH) for the detection of bladder cancer. Materials and Methods: Washing urine samples from 156 patients were evaluated for the detection of bladder cancer. Patients were divided into 3 groups. Group 1 was 106 patients with bladder cancer, group 2 was 30 patients with benign prostatic hyperplasia who underwent transurethral resection of the prostate without bladder cancer, and group 3 had gross hematuria without bladder cancer. The sensitivity and specificity of cytology, NMP22, and FISH were compared. NMP22 positivity was defined as ≥10U/ml. FISH was done with the UroVysionR system and FISH positivity was defined as ≥2 abnormal urothelial cells with an abnormal signal from any out of 4 probes. Results: The overall sensitivity of urine cytology, NMP22, and FISH was 60.4%, 75.5%, and 84.9%, respectively (p<0.001). The overall specificity of cytology, NMP22, and FISH was 96.7%, 83.3%, and 93.3%, respectively (p=0.168). In group 3, the false-positive rates of cytology, NMP22, and FISH were 20.0%, 55.0%, and 10.0%, respectively. In these patients with gross hematuria, the false-positive rate with NMP22 was significantly higher than with cytology or FISH (p=0.004). The sensitivity of cytology, NMP22, and FISH in low-grade bladder cancer patients was 25.9%, 51.9%, and 77.8%, respectively, and that in pTa-1 bladder cancer patients was 40.6%, 65.6%, and 78.1%, respectively. In low-grade or in pTa-1 patients, the sensitivity of the three diagnostic tools was significantly different (low grade; p<0.001, pTa-1; p<0.001). Conclusions: FISH is more sensitive in low-grade bladder cancer than is urine cytology and can be used as a diagnostic tool for the detection of primary and recurrent bladder cancer. NMP22 was affected by gross hematuria and thus has limitations for screening of bladder cancer. However, it can be used to follow-up bladder cancer. (Korean J Urol 2009;50:6-11)