Patterns of chromosomal imbalances in muscle invasive bladder cancer

Cytogenetic investigations of bladder cancer suggested that development and progression is characterized by specific chromosomal aberrations. In order to identify genetic changes linked to muscle invasive tumors and metastati c growth we analyzed 67 bladder carcinomas (30 pT1 and 37 pT2-4) by means o f comparative genomic hybridization (CGH). The most frequent changes were g ains of chromosome 1q (54%), 8q (54%), 17q (49%), 2p (30%), 12 (30%), 5p (2 5%), 3q (24%) and 6p (24%) as well as losses of 11p (43%), 8p (42%), 9p (36 %), 11q (34%), 2q, 4q, 5q (30% each), 9q (27%) and 10q (27%). Previously no t described amplifications were found at 5p11-p13, 7q21-q31, 9p24 and 17q24 -q25. Gains of 3q, 7p, and 18p were markedly more frequent in pT2-4 in comp arison to pT1 carcinomas but the difference did not reach statistical signi ficance. Non-metastatic tumors showed more aberrations on average than meta static carcinomas, although no particular change was found to be predominat ing in either group. Our data confirm previous findings of strong genetic s imilarities between minimally and deeply invasive bladder carcinomas but ar gue for differences between metastatic and non-metastatic disease.