Clinical utility of a multiprobe FISH assay in voided urine specimens for the detection of bladder cancer and its recurrences, compared with urinary cytology.

OBJECTIVES

To evaluate the clinical utility of a Multi-color FISH (fluorescence in situ hybridization) assay in voided urine specimens for the detection of bladder cancer and its recurrences, comparing the results with those afforded by urinary cytology.

METHODS

Voided urine samples from 86 patients were obtained for urine cytology and FISH analysis. The latter was performed using a mixture of fluorescent labeled DNA probes for the centromeric regions of chromosomes 3, 7 and 17, and the 9p21 region. Cystoscopy with biopsy or tumor resection was performed in all patients, comparing the pathological results with the cytological and FISH findings.

RESULTS

Urinary cytology affords an overall sensitivity of 63.8%, the figure being 25% for grade 1, 66.6% for grade 2 and 94.7% for grade 3 tumors. The sensitivities for FISH were 53.3% for grade 1, 83.3% for grade 2 and 100% for grade 3 tumors, with an overall sensitivity of 80.4%. The specificities of urinary cytology and FISH were 86.1 and 85.3%, respectively.

CONCLUSIONS

FISH improves the sensitivity rates obtained with urine cytology for bladder cancer detection in all tumor grades and stages, and offers similar specificity. FISH doubles the accuracy of urinary cytology in application to low grade-stage tumors, and detects all high grade infiltrating tumors.