The performance characteristics of the bladder tumour antigen test

Objective To evaluate the specificity and sensitivity of the Bard bladder tumour antigen (BTA) (Bard Inc, Covington, USA) test. Patients and methods The performance of the BTA test was assessed prospectively in 98 patients (30 women and 68 men, mean age 64 years, median 67, so 14.8) undergoing cystoscopy for various indications, The urine of the patients was assessed using the BTA test, cytology. culture and a dipstick test for haematuria, and the results compared with those from cystoscopy as the 'standard'. Results The overall specificity for the BTA test was 79% and the sensitivity 37%. The sensitivity was higher than for urine cytology (33%) but less than for the dipstick test (59%), The specificity was less than for cytology (100%) but higher than for the dipstick test (66%). Conclusion The BTA test is a rapid, non-invasive qualitative test identifying degradation products of the basement membrane of the transitional cell epithelium. It represents an advance in the search for a 'tumour marker' for carcinoma of the bladder, The specificity is acceptable but the sensitivity relatively low, which limits its value in everyday practice. Further research and development are needed to improve sensitivity.