Multiprobe FISH for enhanced detection of bladder cancer in voided urine specimens and bladder washings

The aim of this study was to evaluate the UroVysion (Vysis, Downers Grove, IL)fluorescence in situ hybridization (FISH) test for improved detection of bladder cancer in urinary specimens. Three groups of specimens were examin ed including voided urine specimens (1) collected before resection of bladd er cancel; (2) from cystoscopically negative bladders of patients with prev ious bladder cancer and (3) from patients with benign prostatic hyperplasia (controls). FISH positivity was defined as more than 2 urothelial cells wi th an abnormal signal copy number of at least I of the 4 probes. FISH was p ositive in 1 of 27 control specimens and in 33 (73%) of 45 pTa, 12 (100%) o f 12 pTI, and 13 (100%) of 13 pT2-4 tumors. The results were similar in a s eries of 68 bladder washings. In addition, FISH of voided urine specimens w as positive in 5 of IO patients with negative follow-up cystoscopy results. Subsequent recurrence was found in 4 of these patients but in none of 5 pa tients with FISH-negative results. Multiprobe FISH markedly improves the se nsitivity and specificity of cytology for the detection of bladder cancer i n urine specimens.