Fluorescent in situ hybridization as a predictor of relapse in urothelial carcinoma

To assess the value of the study of chromosomal alterations by fluorescent in situ hybridization in a series of patients diagnosed of urothelial carcinoma and a minimum follow up of twenty four months, as well as evaluate its putative predictive potential.

The overall series includes 338 samples from 98 patients with 84 episodes of urothelial carcinoma. A subgroup of 24 patients who had at least one recurrence during the follow up was used to evaluate the predictive potential of the test. Three categories were considered (positive coherent episode, negative coherent episode, and incoherent episode) depending on the relationship between the fluorescent in situ hybridization result in the concomitant study of the new episode and those of the preceding samples.

Fluorescent in situ hybridization showed higher sensitivity regardless of grade, negative predictive value and accuracy, while specificity and positive predictive value were superior with conventional cytology. In the recurrence, series 19/29 episodes were coherent, 11/19 were positive coherent with urothelial carcinoma all high grade and 8/19 negative coherent, most low grade.

Fluorescent in situ hybridization test shows good sensitivity during a follow up of twenty four months and is able to predict recurrence, especially in cases of high grade. Our data demonstrate the existence of urothelial carcinomas without detectable chromosomal abnormalities by currently available methodology. The results support a multidisciplinary follow up combining fluorescent in situ hybridization, cytology and cystoscopy.