Bladder tumor antigen assay as compared to voided urine cytology in the diagnosis of bladder cancer

Background: The study was aimed at comparing the diagnostic accuracy of the quantitative bladder tumor antigen (BTA) TRAK™ immunoassay with exfoliative urine cytology in the detection of primary and recurrent bladder cancer. Methods: The analysis was carried out on 194 high risk patients undergoing a diagnostic cystoscopy, 279 patients with previous history of transitional cell carcinoma awaiting a follow-up cystoscopy, and 45 healthy controls. Urine cytology was performed by a skilled cytopathologist on three consecutive samples. Results: BTA TRAK values resulted significantly higher in tumor positive cases than in absence of bladder tumor for both groups of patients. Non neoplastic urothelial diseases as well as the absence of mucosal abnormalities were associated with a marked increase in BTA TRAK levels with respect to the control group. Overall sensitivity and specificity was 63 and 63% for BTA TRAK (cut-off 34 U/ml), and 68.3 and 73.4% for urine cytology, respectively. The diagnostic advantage of urine cytology was maintained when patients were stratified by tumor grade. Conclusions: The clinical performance of the BTA TRAK in the detection of primary or recurrent bladder cancer is acceptable and reproducible as shown by similar results with previous reports, although urine cytology performed on three samples showed the highest sensitivity and specificity.