Effect of intravesical instillations on the human complement factor H related protein (BTA stat) test

Objectives:The BTA stat is a rapid, non-invasive, qualitative urine test th at detects bladder tumor-associated antigen (human complement factor H rela ted protein) in urine. The sensitivity of this test is superior to that of urine cytology in detecting primary and recurrent tumors of the urinary bla dder. Intravesical instillations are widely used to avoid recurrences and e ven progression. The objective of this study was to evaluate the effect of intravesical treatments on the BTA statTest. Methods: 501 consecutive patients followed up for bladder cancer were studi ed, of which 490 were eligible for analysis. Three hundred and twenty-seven (66.7%) of the patients had no history of intravesical treatments, whereas the remaining 163 (33.3%) had received treatments: 66 (40.5%) at the time of evaluation. A voided urine sample was obtained prior to cystoscopy and s plit for culture and BTA stat testing. The overall sensitivity and specific ity were calculated and compared to the patients with no, past and present instillations. Results:The overall sensitivity for the BTA statTest was 56.6%, and the spe cificity was 76.4%. The specificity of the BTA statTest was 80.7, 70.7 and 65.3% in those with no, past or present intravesical instillation treatment s, respectively. The difference in specificity between those with no and pr esent instillations was significant (p = 0.023), whereas the notable differ ence between those with no and past instillations did not reach significanc e (p = 0.076), nor was the difference between patients with past and presen t instillations significant (p = 0.558). Present instillation of mitomycin C had the strongest adverse effect on the test as the specificity was only 25.0%, whereas past treatment did not interfere with testing. The adverse e ffect of BCG treatment on testing extended. Conclusion: The overall specificity of the test is decreased in patients re ceiving intravesical treatments, whereas past treatments did not interfere with testing in general. However, the adverse effect of BCG on testing seem s to extend, and therefore it is suggested that the BTA stat Test should no t be used in patients having received BCG, and in those with present instil lation of any type. Copyright (C) 2001 S. Karger AG, Basel.