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 B TA TRAK assay in patients highly suspiscious of bladder cancer. Methods: Th e BIA star and the BTA TRAK tests are two immunoassays that detect human co mplement factor H related protein in urine, employing the same antibody pai r. The BTA stat is a qualitative test which can be performed in a consultat ion setting. The BTA TRAK is a quantitative test that is performed in the l aboratory. Consecutive patients highly suspicious of bladder cancer were in cluded in this prospective blinded trial to assess the clinical performance s 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 bet ween BTA TRAK and BTA stat as regards specificity (20/32 and 23/32 true-neg ative 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 detecti on of low-grade and low-stage bladder cancer.