Prospective evaluation 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: The finding of atypical cytology is confusing for clinicians and it represents a management dilemma. We prospectively evaluated the clinical usefulness of fluorescence in situ hybridization assay for treating patients with atypical cytology who are at risk for bladder cancer. Materials and Methods: Between May 2006 and June 2007 every patient who underwent cystoscopy and cytology with atypical or suspicious cytology underwent a reflex UroVysion (R) test. A comprehensive review was then performed to evaluate clinical and pathological data on each patient. Results: The population comprised 50 patients with no history of cancer and 70 who underwent cystoscopy for cancer surveillance. Fluorescence in situ hybridization assay was positive in all patients with cystoscopically visualized lesions whether they did or did not have a history of bladder cancer (positive predictive value 100%). In patients with equivocal cystoscopy and a history of cancer fluorescence in situ hybridization detected all 5 high grade tumors but it was false-negative for a low grade Ta tumor. In patients with equivocal cystoscopy and no prior cancer the positive predictive value was 50% and there was no false-negative assay result. In patients with negative cystoscopy and a history of cancer fluorescence in situ hybridization detected 3 cancers, including bladder carcinoma in situ in 2 and prostate carcinoma in situ in 1. In patients with no prior cancer and negative cystoscopy fluorescence in situ hybridization detected the only cancer (a high grade ureteral tumor) without yielding any false-negative results. Conclusions: This prospective evaluation of a reflex fluorescence in situ hybridization assay in patients with atypical cytology shows that the assay was unnecessary in patients with obvious tumors on cystoscopy but it was beneficial in patients with equivocal or negative cystoscopy. Fluorescence in situ hybridization assay identified all high grade cancers. It may help avoid unnecessary evaluation in patients with atypical cytology and equivocal or negative cystoscopy, while identifying those who would need further evaluation.