Analysis of false-positive BTA stat Test results in patients followed up for bladder cancer

Objectives. To evaluate the role of a positive BTA stat Test result in pati ents with negative cystoscopic findings. Methods. Five hundred one consecutive patients in follow-up for bladder can cer were studied. A voided urine sample was obtained before cystoscopy and split for culture, cytology, and BTA stat testing. In the case of a positiv e BTA stat Test, but negative cystoscopic findings, patients underwent addi tional investigations. Results. Of 501 patients, 133 (26.5%) had bladder cancer recurrence at cyst oscopy, of which the BTA stat Test detected 71 (53.4%); only 21 of the case s (17.9%) were detected by cytologic examination. Of the remaining 368 pati ents with no visible tumor at cystoscopy, 96 (26.1%) had a positive BTA sta t Test result. Fifty-five of those (57.5%) underwent intravenous urography or renal ultrasound and random biopsies, and an additional 9 recurrences (1 6.4%) were detected. Of those 46 patients who had a true false-positive BTA stat Test, 3 (5 of 43, 7.0%) had recurrence at the next follow-up cystosco py, 4 (8.7%) had a urine infection, and 8 (17.4%) had ongoing intravesical instillations; the latter two percentages were significantly higher than am ong those with true-negative BTA stat Test results (0% and 6.8%, respective ly). Conclusions. Patients with a positive BTA stat Test result but negative cys toscopic findings have about a 16% risk of an undetected recurrence. False- positive results may be due to present instillation treatment and urine inf ection, and the predictive value of a BTA stat Test for subsequent recurren ce seems relatively low. UROLOGY 57: 680-684, 2001. (C) 2001, Elsevier Scie nce Inc.