Prospective Validation of the Clinical Usefulness of Reflex Fluorescence In Situ Hybridization Assay in Patients With Atypical Cytology for the Detection of Urothelial Carcinoma of the Bladder

Purpose: We previously prospectively evaluated the clinical usefulness of a fluorescence in situ hybridization assay for treating patients with atypical cytology results at risk for bladder cancer. This study is a prospective validation the usefulness of fluorescence in situ hybridization in this setting. Materials and Methods: Between June 2007 and January 2009 every patient who underwent cystoscopy and cytology with atypical cytology underwent a reflex UroVysion® test. A comprehensive review was then performed to evaluate clinical and pathological data on each patient. Results: The study population comprised 108 patients with no history of cancer and 108 who underwent cystoscopy for cancer surveillance. In patients with cystoscopically visualized lesions UroVysion had a positive predictive value of 100% but there were false-negative results. In patients with equivocal cystoscopy and a history of cancer all 4 high grade tumors were detected and there were no false-negative findings. In patients with equivocal cystoscopy and no prior cancer the positive predictive value was 100% and there were no false-negative results. In patients with negative cystoscopy the UroVysion test detected all cancers but the positive predictive value was 10% and 29% in patients with and without a history of cancer, respectively. Conclusions: This prospective study of a reflex fluorescence in situ hybridization assay in patients with atypical cytology validates our previous findings. In patients with atypical cytology and obvious tumor on cystoscopy the assay was unnecessary but it was beneficial in those with equivocal or negative cystoscopy results. The fluorescence in situ hybridization assay identified all urothelial carcinoma tumors in patients with equivocal or negative cystoscopy. In patients with equivocal or negative cystoscopy and atypical cytology, a reflex fluorescence in situ hybridization assay may help avoid unnecessary evaluation while identifying those who would need further evaluation.