Genetic aberrations detected by comparative genomic hybridization in biliary tract cancers

In order to elucidate cytogenetic changes characteristic of biliary tract c ancer, we examined the genetic imbalances in 18 biliary tract cancers using comparative genomic hybridization (CGH). The most common sites of increase s in copy number, in order of frequency, were 17q (33% of the cases), 5p (2 8%), 3q (22%), 7p (22%), 8q (22%), and 12p (22%), whereas copy number decre ases of 6q (28%), 18q (28%), 4q (22%), 5q (22%), and 9p (22%) were frequent . The average number of chromosomal aberrations was significantly greater i n stage IV than in stage III tumors (7.9 vs. 2.2/tumor, p < 0.05). The freq uent aberrations detected in this study may be related to the development a nd/or progression of biliary tract cancers; This is the first report on CGH of biliary tract cancers.