GENOMIC HETEROGENEITY IN BLADDER-CANCER AS DETECTED BY FLUORESCENCE IN-SITU HYBRIDIZATION

Objective To investigate the relationship between genomic heterogeneit y and tumour grade, stage and DNA content in 30 transitional cell carc inomas (TCCs) of the urinary bladder. Materials and methods Tissue spe cimens from 30 patients (25 men and five women) with newly diagnosed T CC of the urinary bladder were examined for genomic heterogeneity usin g fluorescence in situ hybridization (FISH) with chromosome-specific D NA probes; the copy number of pericentromeric sequences on chromosomes 7, 9 and 17 was detected within interphase nuclei in contact preparat ions from the tumour specimens. Results The aneusomy of chromosomes 7, 9 and 17 was significantly higher in aneuploid than in diploid tumour s (P < 0.001). Tumour grade and stage were strongly associated with an eusomy for chromosome 17 (P < 0.01, P < 0.001, respectively). The aneu somy of chromosomes 7 and 9 were significantly correlated with increas ing tumour stage (P < 0.001), but not with tumour grade. Conclusion Th ese results suggest that the measurement of aneusomy using FISH, espec ially for chromosome 17, in bladder cancer may offer a new objective a nd quantitative assay of the biological potential of individual tumour s.