ABSTRACT
INTRODUCTION AND OBJECTIVES: The non-invasive detection of urothelial carcinoma remains challenging. The aim of this study was the prospective evaluation of urine markers for bladder carcinoma. We compared the NMP 22 and BTAstat tests with immunocytology (IC) using monoclonal antibodies against the Lewis X antigen and against 486p3/12. METHODS: NMP 22 and BTAstat were performed on urine samples, and IC with 486p3/12 and Lewis X staining was performed on urine samples as well as bladder wash specimens ( n=146) in patients ( n=115) undergoing transurethral resection on suspicion of bladder cancer (70 specimens) or follow up cystoscopy because of a history of bladder cancer (76 specimens). Bladder cancer was detected in 54 patients (pTa: n=25, pT1: n=20, pT2: n=8, CiS: n=1). Cut-off levels were 10 U/ml for the NMP 22, 30% positive cells for 486p3/12, and 5% positive cells for the Lewis X test. RESULTS: The BTAstat test was positive in 65 (44.5%) cases, the NMP 22 in 69 (47.3%) cases, IC with 486p3/12 and the Lewis X was positive in 52 (35.6%) and 109 (74.7%) cases, respectively. Sensitivity was 70.3% (BTAstat), 68.5% (NMP 22), 94.4% (Lewis X), and 68.5% (486p3/12), respectively. The specificity was 70.6% (BTAstat), 65.2% (NMP 22), 36.9% (Lewis X), and 83.6% (486p3/12), respectively. Among the patients with a false positive test 2/22 (9.0%) patients (BTAstat), 2/25 (8%) patients (NMP 22 test), 4/43 (9.3%) patients (Lewis X), and 3/11 (27%) patients (486p3/12), respectively, suffered from tumor recurrence. In contrast, among the patients with a correct negative test 2/39 (2.0%) (BTAstat), 2/36 (0.5%) (NMP 22), 0/18 (0%) (Lewis X), and 1/50 (2.0%) (486p3/12), respectively, suffered from tumor recurrence. CONCLUSIONS: IC with the Lewis X revealed a higher sensitivity than all of the tested, commercially available methods. Because of its high sensitivity and its high negative predictive value, the Lewis X test may be useful for screening a high-risk population. Patients with a false positive 486p3/12 test have an increased risk of tumor recurrence when compared with patients with a correct negative test.
