Prognostic significance of nondiagnostic molecular changes in urine detected by UroVysion fluorescence in situ hybridization during surveillance for bladder cancer.

Objectives: To determine the outcomes for patients with nondiagnostic fluorescence in situ hybridization (FISH) (ie, < 4 gains of chromosomes 3, 7, or 17 in < or = 3 cells). FISH detects urothelial carcinoma and is especially beneficial in patients with negative or atypical urine cytology findings. A positive result is defined as a gain of > or = 2 chromosomes (3, 7, or 17) in 4 cells, isolated loss of 9p21 in 12 cells, or isolated gains of only 1 chromosome in > or = 10% of cells. Most FISH-positive patients will develop recurrent urothelial carcinoma within 1 year.

Methods: We compared the data from 149 patients with a nondiagnostic FISH result and > or = 30 months of follow-up with the data from patients with a negative FISH result from the same period. The time to conversion to a positive FISH result or the development of a bladder tumor was recorded.

Results: Patients with nondiagnostic FISH results had significantly greater rates of progression to positive FISH findings or the development of a bladder tumor than did patients with negative FISH findings. Most progression occurred within 1 year. Patients with nondiagnostic FISH results and concurrent negative cytology and cystoscopy had a very low risk of developing recurrent disease, similar to that found with truly negative FISH results.

Conclusions: Nondiagnostic FISH results are related to a greater risk of progression to positive FISH results and tumor recurrence than those with negative FISH findings. However, after controlling for negative cytologic and cystoscopic status, a nondiagnostic FISH result does not appear to be an independent predictor of disease recurrence, and aggressive investigation is not warranted.