Comparison of two qualitative assays, the UBC rapid test and the BTA stat test, in the diagnosis of urothelial cell carcinoma of the bladder.

Objectives: To compare the diagnostic value of two rapid tests, the bladder tumor antigen (BTA stat) test and the newly developed urinary bladder cancer (UBC) Rapid test, in patients having symptoms suggestive of urothelial cell carcinoma (UCC) and patients being followed up after transurethral resection.

Methods: One hundred eighty patients with a mean age of 65.8 years (range 22 to 92) were included in the present study. The tests were performed on voided urine samples. Fifty-seven patients had symptoms suggestive of UCC and 123 patients were being followed up after complete transurethral resection of UCC. The voided urine was evaluated by the BTA stat and UBC Rapid test, which detects cytokeratins 8 and 18. All patients underwent subsequent cystoscopic evaluation and biopsy of any suspicious lesion.

Results: In 53 patients with histologically proved UCC, the BTA stat had a sensitivity of 52.8% and the UBC Rapid test of 66%. According to the histologic stage, the sensitivity of the BTA stat was 42.8% in pTa tumors, 61.5% in pT1, and 70% in pT2 or higher tumors. The sensitivity of the UBC test was 60.7% in pTa, 69. 2% in pT1, and 80% in pT2 or higher tumors. For histologic grades 1 to 3, the sensitivity was 38.8%, 52.6%, and 68.7% for the BTA stat and 44.4%, 78.9%, and 75% for the UBC Rapid test, respectively. The specificity was 70% and 90% for the BTA stat and UBC Rapid test, respectively.

Conclusions: The UBC Rapid test was superior to the BTA stat in both sensitivity and specificity. Both assays are simple office procedures and require no special knowledge. However, they cannot replace, but only lower, the number of cystoscopies during the follow-up of patients with previous UCC of the bladder.