Mapping of chromosomal gains and losses in prostate cancer by comparative genomic hybridization

Comparative genomic hybridization (CGH) allows detection of chromosomal imbalances in whole genomes in a comprehensive manner. With this approach, ten cases of prostate cancer (seven primary tumors and three metastases) were analyzed. Frequent chromosomal gains detected by CGH involved chromosome arms 7q, 8q, 9q, and 16p, and chromosomes 20 and 22, as well as frequent losses of chromosome arms 16q and 18q, in at least three of the ten cases. Overrepresentation of chromosome arm 9q has not been described in published reports. The CGH data were compared with results of a loss of heterozygosity (LOH) study, in which complete allelotyping was performed in the same prostate tumors with 74 different polymorphic markers. In general, a high concordance between the CGH and LOH results was observed (92%). Tumors revealing discrepancies by CGH and LOH analysis were investigated further by interphase cytogenetics, and the resulting picture regarding the genomic alterations is discussed in detail.