Objective: To compare the BTA stat test (BTA stat), a new one-step immunochromatographic assay that can be performed in the urologist's office or in the laboratory, to voided urine cytology and bladder wash cytology (cytology) in the diagnosis and monitoring of cancer of the bladder (BC).
Methods: BTA stat and cytology were performed in a double-blinded, prospective, clinical study on specimens from 240 subjects (68 females; mean age of subjects: 64 years) suspected of having BC.
Results: In 107 subjects with final diagnoses of BC confirmed by cystoscopy or cystoscopy and biopsy, the overall sensitivities of BTA stat and cytology were 65 and 33%, respectively. For tumor grades I, II, and III, the sensitivities of BTA stat were 39, 67 and 83%, respectively. Those of cytology were 4, 20 and 69%. Nine subjects had a diagnosis of 'suspicious for bladder cancer'. The specificities of BTA stat and cytology in the 124 subjects without BC were 64 and 99%, respectively. In the subjects with a history of BC (n = 74), the specificities of BTA stat and cytology were 72 and 99%, respectively. The specificity of BTA stat was lower in subjects with benign or malignant genitourinary disease other than BC (46%) than in subjects without genitourinary disease (71%).
Conclusions: The BTA stat test is considerably more sensitive than cytology in the detection of BC and can replace cytology as an adjunct to cystoscopy in the diagnosis and follow-up of patients with BC. However, due to low specificity, BTA stat should not be used without first ruling out potential interferences such as infections, renal disease and cancer, or genitourinary trauma.