R. De Vita, P. Eleuteri, D. Cavallo, M.G. Grollino, G.Calugi, M. Gallucci and F. Di Silverio. Environmental Epidemiology ENEA Casaccia, Rome; Urologic Div. "Cristo Re" Hospital Rome; Urologic Dept. Univ of Rome, Rome, Italy.

Bladder TCC are a heterogeneus group of tumours in biological and behaviour terms and these differences suggest that there is not a single tumoral progression pathway. Since bladder TCC can be followed in their natural history, they offers the potencial of correlating specific aberrations with progression and recurrence and studing early genetic events. We have applied the flourescent in situ hibridization (FISH) to interphase cells of bladder TCC from biopsies and wasing to evaluate specific numerical chromosome alterations. Flow cytometry analysis was also performed on the same samples to monitor cellular heterogeneity in terms of ploidy level. These analytical approaches were used on both biopsies and washing to compare alterations in exfoliated cells and in tumoral biopsy. The ploidy of chromosomes 9, 8, 11 and 1 was investigated utilizing a specific centromeric probe. The detection of hibridization was performed with fluorescein- avidin and the slides were analyzed to calculate the number of spots/nucleus indicating chromosomal aberrations. The samples used for cytometric analysis were stained with EB+MI dyes and measured by a PAS II are lamp flow cytometer.We obteined evaluable and comparable results in every case of bladder cancer analyzed for both FISH and DNA FCM analyses. Moreover different ploidy conditions in some cases of bladder TCC between biospy and whasing samples was observed. In particular, in 68% of cases the DNA ploidy observed in whashing-samples and in biospy samples of the same patient were different in terms of number of clones and/or in terms of DNA index. The results obtained by FISH analysis showed in the most of cases the 9 monosomy. This condition was observed both in washing samples and in biopsies with different cellular frequency.