Reflex fluorescence in situ hybridization assay for suspicious urinary cytology in patients with bladder cancer with negative surveillance cystoscopy

Objective: To assess the ability of reflex UroVysion fluorescence in situ hybridization (FISH) testing to predict recurrence and progression in patients with non-muscle-invasive bladder cancer (NMIBC) with suspicious cytology but negative cystoscopy.

Patients and methods: Patients under NMIBC surveillance were followed with office cystoscopy and urinary cytology every 3-6 months. Between March 2007 and February 2012, 500 consecutive patients with suspicious cytology underwent reflex FISH analysis. Clinical and pathological data were reviewed retrospectively. Predictors for recurrence, progression and findings on subsequent cystoscopy (within 2-6 months after FISH) were evaluated using univariate and multivariate Cox regression.

Results: In all, 243 patients with suspicious cytology also had negative surveillance cystoscopy. Positive FISH was a significant predictor of recurrence (hazard ratio [HR] = 2.35, 95% confidence interval [CI]: 1.42-3.90, P = 0.001) in multivariate analysis and for progression (HR = 3.01, 95% CI: 1.10-8.21, P = 0.03) in univariate analysis, compared with negative FISH. However, positive FISH was not significantly associated with evidence of tumour on subsequent surveillance cystoscopy compared with negative FISH (odds ratio = 0.8, 95% CI: 0.26-2.74, P = 1).

Conclusions: Positive FISH predicts recurrence and progression in patients under NMIBC surveillance with suspicious cytology but negative cystoscopy. However, there was no association between the FISH result and tumour recurrence in the immediate follow-up period. Reflex FISH testing for suspicious cytology might have limited ability to modify surveillance strategies in NMIBC.