BTA stat and BTA TRAK:: A comparative evaluation of urine testing for the diagnosis of transitional cell carcinoma of the bladder

Objective: We compared the BTA (bladder tumor antigen) stat test with the BTA TRAK assay in patients highly suspiscious of bladder cancer. Methods: The BIA star and the BTA TRAK tests are two immunoassays that detect human complement factor H related protein in urine, employing the same antibody pair. The BTA stat is a qualitative test which can be performed in a consultation setting. The BTA TRAK is a quantitative test that is performed in the laboratory. Consecutive patients highly suspicious of bladder cancer were included in this prospective blinded trial to assess the clinical performances of the two methods. Results: A total of 81 patients were tested using BTA stat and BTA TRAK before cystoscopy. A tumor was identified in 49 patients. BTA TRAK (38/49 true-positive cases) was more sensitive than BTA stat (32/49) in detecting bladder cancer (p < 0.05). When considering the subgroups of bladder cancer by stage and grade, the difference remained significant for low-grade and low-stage tumors. There was no significant difference between BTA TRAK and BTA stat as regards specificity (20/32 and 23/32 true-negative cases, respectively; p = 0.2). Conclusion: BTA TRAK with a cutoff of 14 U/ml had a significantly higher sensitivity than BTA stat in the detection of low-grade and low-stage bladder cancer.