Improved Detection of Urothelial Carcinomas with Fluorescence Immunocytochemistry (uCyt+ Assay) and Urinary Cytology: Results of a French Prospective Multicenter Study

The aim of the study was to assess the sensitivity and specificity of fluorescence immunocytochemistry (uCyt+ assay) as combined with urinary cytology for detection of primary and recurrent urothelial carcinomas. We analyzed 694 urinary samples from 236 new symptomatic patients and 458 patients followed after transurethral resection (TUR) for bladder tumor. Lesions suspicious for cancer at cystoscopy were sampled by biopsies or TUR. Sensitivity and specificity of tests were calculated using cystoscopy and histopathology, whether or not combined as gold standards. In new symptomatic patients, sensitivity of uCyt+ was 40%, 88.2%, and 76.7%, whereas that of urinary cytology was 30%, 70.6%, and 83.3%, respectively, in G1, G2, and G3 tumors. In follow-up cases, sensitivity of uCyt+ was 61.9%, 66.7%, and 76.9%, whereas that of urinary cytology was 38.1%, 58.3%, and 64.1%, respectively, in G1, G2, and G3 tumors. The combination of uCyt+ and urinary cytology significantly increased mean sensitivity in newly diagnosed cases (86.4% versus 71.2% with urinary cytology only, p < 0.05), as well as in patients followed after TUR (79.3% versus 55.2%, p < 0.001). Specificity of uCyt+ and urinary cytology was identical in new patients (83.3%) and was 81.9% and 86.2%, respectively, in patients followed after TUR. In patients with negative cystoscopy, positive uCyt+ tests had a strong predictive value for tumor recurrence at 1 year (47.0% versus 11.9% in patients with negative assay, p < 0.01). We conclude that combining uCyt+ with urinary cytology improves the detection of urothelial carcinomas as well in patients with symptoms suggesting bladder cancer as in those followed after treatment.