Determination of a New Cut-Off Value for the Urinary BTAtrak to Optimize the Detection of Recurrences in the Follow-Up of Patients with Superficial Bladder Carcinoma

Abstract

The present study aimed to prospectively reassess the cut-off value of the urinary BTAtrak assay in order to optimize the detection of high and middle risk recurrent tumors during the follow-up of superficial bladder cancer. Patients and Methods: We prospectively investigated sensitivity and specificity values of BTAtrak (cut-off: 8 U/ml), cytology, hemoglobin dipstick and their combinations in 956 patients monitored for bladder cancer recurrence. All of the patients (n = 2) with upper urinary tract tumours (UUTT) showed a positive BTAtrak and were not included in the study. We found 215 bladder neoplasms, 149 were papillary and the remaining 66 were solid tumors. There were 115 (53.5%) single tumors and 100 (46.5%) multiple tumors. The mean size of the tumors was 1.78 ± 1.8 cm with 80 (37.2%) minor than 0.5 cm, 103 (47.9%) from 0.5 to 3 cm and 32 (14.9%) tumors greater than 3 cm. Results: BTAtrak (cut-off: 8 U/ml) plus cytology demonstrated the highest overall sensitivity and detected all high-risk tumors (Ta-1G3/Tis and T2-4). Specificity increased considerably when radiotherapy, urinary tract infection (UTI), urethral catherization as well as intravesical instillations within 3 months before BTAtrak determination were not included. The combinations of cytology and BTAtrak resulted negative in 42.6% of cases with a BTAtrak cut-off of 8 U/ml. Conclusion: The combination of cytology and BTAtrak using a lower cut-off level (8 U/ml) demonstrated to be a very sensitive marker to detect most of dangerous tumors in the follow-up of superficial bladder cancer.