Background and purpose: Fluorescence in-situ hybridization (FISH) assay has been approved by the U.S. Food and Drug Administration for the detection of recurrent transitional-cell carcinoma (TCC) of the bladder and in the initial workup of hematuria. In this study, we retrospectively reviewed our initial 94 FISH specimens taken from patients monitored for upper-tract TCC.
Patients and methods: Between 2004 and 2007, 43 patients had one or more FISH assays performed as part of the workup and management of upper-tract TCC. Of 94 specimens sent for FISH analysis, 25 voided specimens collected at an outpatient encounter and 40 specimens taken as a bladder wash or selective upper-tract washing under anesthesia were followed by upper-tract endoscopy. The sensitivity and specificity of the FISH assay for detecting urothelial lesions in this population were calculated and compared with cytology specimens from the same sources.
Results: Overall sensitivity of FISH in the detection of TCC in this population was 52%, compared with 26% for urinary cytology. Both FISH and cytology showed superior sensitivity for high-grade (79% and 50%, respectively) nu low-grade tumors (41% and 12%, respectively). Selective upper-tract washings were more sensitive and specific for upper-tract TCC than bladder washings or voided specimens.
Conclusions: While the sensitivity of FISH for upper-tract TCC parallels its performance in bladder cancer, the preponderance of low-grade, recurrent disease in the population undergoing surveillance and minimally invasive therapy for upper-tract TCC may limit its usefulness in this setting. Until a high-sensitivity marker for low-grade urothelial lesions is developed, the surveillance of upper-tract TCC will continue to require vigilant direct visual inspection.