Chromosomal numerical aberrations in bladder cancer detected by fluorescence in situ hybridization (FISH)

Background: Chromosomal aberration and DNA ploidy pattern are regarded as prognostic markers of the bladder cancer. In this paper, numerical chromosomal aberrations were analysed by interphase fluorescence in situ hybridization (FISH) for the cases with bladder cancer.

Methods: FISH was carried out on touch smear of 35 cases of transitional cell carcinoma of the urinary bladder. DNA probes were digoxigenin labeled alpha/beta-satellite probes for chromosome 1, 7, 9, 11, 17, Y. FISH signals were counted using confocal laser microscope (LSM GB 200, OLYMPUS. Touch smear preparations were also examined with image cytometer (CAS 200, Becton Dickinson) and DNA index was obtained.

Results: Numerical chromosomal aberrations were observed in 9 of 21 (42.9%) diploid cases and in all 14 non-diploid cases. Among 6 kinds of chromosome examined imbalance was observed and most common imbalance was loss of chromosome 9 (11 cases, 32.4%).

Conclusions: Even in the diploid tumors, chromosomal aberration was observed. Combined analysis of chromosomal aberration and DNA ploidy pattern was easily and quickly performed in our series. Clinical application could be possible and possess diagnostic and prognostic value.