Multicenter evaluation of the role of UroVysion FISH assay in surveillance of patients with bladder cancer: does FISH positivity anticipate recurrence?

Background: The significance of a positive UroVysion FISH assay is uncertain in patients with normal cystoscopy. This multicenter study evaluates the clinical significance of a positive FISH assay in patients with no visible tumor and excluding those with a positive cytology. Methods: A multi-institutional, retrospective study of patients with a history of urothelial carcinoma of the bladder identified 664 patients with a FISH assay after excluding those with cystoscopic evidence of a tumor and/or positive cytology. Our primary end point was cancer recurrence, defined by biopsy. Progression was defined as recurrence with a tumor stage ≥T2. Statistical analyses were performed using Fisher’s exact test as a one-tailed test and Chi-square test with significance at 0.05, using SPSS^® version 19.0 (SPSS Inc., Chicago, IL, USA). Results: Of the 664 patients in this study, tumor stage was Ta (363, 55 %), T1 (183, 28 %), and CIS (109, 16 %) and most were high grade (440 pts, 66 %). The median follow-up was 26 months (3–104 months), and 277 (41.7 %) patients were recurred. In patients who were FISH positive, mean time to recurrence was 12.6 months, compared to 17.9 months if FISH negative (p = 0.03). In univariate analysis, atypical cytology, positive FISH, cystoscopic findings (atypical vs. normal), and previous intravesical therapy were associated with recurrence (p < 0.05). On multivariate analysis, pathologic stage, cystoscopic findings, and cytology were independently associated with recurrence (p < 0.05). Progression to ≥T2 disease occurred in 34 (5.1 %) patients in this cohort. On multivariate analysis, only initial T stage and FISH result were found to be independent predictors of progression (p < 0.05). Conclusions: Patients with a positive FISH and atypical cytology are more likely to recur even in the absence of visible tumor. FISH positivity may portend a higher risk for progression. These findings require prospective validation.