Urinary tissue polypeptide-specific antigen for the diagnosis of bladder cancer

Objectives. To evaluate the diagnostic characteristics of the urinary measu rement of cytokeratin tissue polypeptide-specific antigen (TPS) for the det ection of bladder cancer. Methods. Three hundred thirty-five individuals in five groups were studied: group 1, subjects with microhematuria under suspicion for primary bladder cancer; group 2, patients being followed up with scheduled cystoscopic exam inations; group 3, patients in follow-up receiving chemotherapy instillatio ns; group 4, patients with other urologic diseases; and group 5, healthy su bjects. Urine samples belonging to subjects from groups 1, 2, and 3 were co llected immediately before cystoscopy. Additionally, patients from groups 2 and 3 were monitored with urinary TPS for a minimum period between two cys toscopies, TPS was measured by an enzyme immunosorbent assay. Results. Receiver operating characteristic analysis gave a sensitivity of 6 4% and a specificity of 84% at a threshold value of 279 U/L. The positive a nd negative predictive value was 66% and 82%, respectively; accuracy was 77 %. TPS could discriminate the presence of bladder tumor sooner than the sch eduled cystoscopies in 9 of 19 follow-up patients with recurrence. False-po sitive results during follow-up were found in 112 urine samples, one third of which were associated with urinary tract infections. TPS did not appear to be specific for bladder cancer, with elevated results in 45% of patients from group 4, which might lead to clinical misinterpretation of urinary TP S results. Conclusions. Urinary TPS might provide additional information for the detec tion of bladder cancer as an adjunct to cystoscopy. Considering the false-p ositive rates, different urologic diseases should be ruled out before makin g clinical decisions on the basis of elevated urinary TPS results, UROLOGY 55: 526-532, 2000, (C) 2000, Elsevier Science Inc.