Distribution of marker chromosomes in relation to histologic grade in bladder cancer.

Cytogenetic analysis was carried out in 100 tissue specimens from 88 patients with bladder cancer. Using a direct technique of chromosome preparation, analyzable metaphases were obtained in 60 cases. Various chromosomal abnormalities, numerical as well as structural, were found. The frequencies of different marker chromosomes, with the exception of the ring chromosome, increased from grade 1 to grade 3 tumors. The average number of markers per cell was one in G1, four in G2, and eight in G3 tumors. It was possible to make a distinction between structural aberrations occurring in all histologic grades and those specific for the invasive grade 2 and grade 3 tumors.