Objectives: To investigate the clinical utility of fluorescence in situ hybridization (FISH) of voided urine in the detection of bladder cancer and the prediction of its recurrence.
Methods: FISH with centromere-specific probes for chromosomes 9 and 17 was performed to evaluate the chromosomal alterations of exfoliated urothelial cells in voided urine obtained from 44 patients with bladder cancer and 20 controls. The analysis was also performed in 17 patients with bladder cancer after complete transurethral resection to prospectively determine whether FISH can predict tumor recurrence.
Results: The sensitivity to detect bladder cancer by FISH analysis (85%) was significantly higher than that by urine cytologic examination (32%) and by the bladder tumor antigen test (64%) (P <0.0001 and P = 0.026, respectively). The specificity of FISH, cytologic analysis, and the bladder tumor antigen test was 95%, 100%, and 80%, respectively. Among the 17 patients tested after transurethral resection, 7 of 13 FISH-positive patients developed tumor recurrence within the 27-month follow-up period; none of 4 FISH-negative patients developed recurrence during the same period. The recurrence rate in patients with the loss of chromosome 17 was 100%, significantly higher than the 23% for patients without this alteration (P = 0.015).
Conclusions: These findings suggest that FISH analysis of exfoliated urothelial cells in voided urine can efficiently detect bladder cancer and predict its recurrence.