Fluorescence-in-situ-hybridization in the surveillance of urothelial cancers: can use of cystoscopy or ureteroscopy be deferred?

Background: Fluorescence in situ hybridization (FISH) testing may be useful to screen for bladder carcinoma or dysplasia by detecting aneuploidy chromosomes 3, 7, 17 and deletion of the chromosome 9p21 locus in urine specimens. This study aimed to assess the sensitivity, specificity, positive and negative predictive value of FISH in a multi-ethnic population in Asia. Materials and Methods: Patients with haematuria and/or past history of urothelial cancer on follow-up had their voided urine tested with FISH. Patients then underwent cystoscopy/ureteroscopy and any lesions seen were biopsied. The histopathological reports of the bladder or ureteroscopic mucosal biopsies were then compared with the FISH test results. Results: Two hundred sixty patients were recruited. The sensitivity and specificity of the FISH test was 89.2% and 83.4% respectively. The positive (PPV) and negative predictive values (NPV) were 47.1% and 97.9%. By excluding patients who had positive deletion of chromosome 9, the overall results of the screening test improved: sensitivity 84.6%; specificity 96.4%; PPV 75.9% and NPV 97.9%. Conclusions: UroVysion FISH has a high specificity of detecting urothelial cancer or dysplasia when deletion of chromosome 9 is excluded. Negative UroVysion FISH-tests may allow us to conserve health resources and minimize trauma by deferring cystoscopic or ureteroscopic examination.