Chromosomal and DNA patterns in transitional cell bladder carcinoma. A comparative cytogenetic and flow-cytofluorometric DNA study.

Biopsy tissue from 71 bladder tumors in 57 patients was studied by chromosome analysis and flow cytofluorometry. Chromosome analysis was hampered by preparation difficulties and was successful in only 53% of the analyzed tumors. DNA analysis failed to reveal near-diploid deviations, while the grossly aneuploid tumors generally had DNA values 10% to 15% above the numerical chromosome counts. Noninvasive tumors were diploid-near-diploid with occasional markers. Superficially invasive tumors were both diploid-near-diploid and near-tetraploid, but with a chromosome count of only 80 in the latter cases. Deeply invasive tumors tended to be triploid on DNA analysis, and had chromosome counts in the vicinity of 60. In addition to single chromosome abnormalities, increased malignancy apparently is also associated with an increased total number of chromosomes. A tetraploid DNA level seems to represent a more stable genome, although chromosomes show gross abnormalities including markers.