Comparative genomic hybridization analysis of genetic aberrations associated with development and progression of biliary tract carcinomas

BACKGROUND. Little is known about genetic aberrations associated with devel opment and progression of biliary tract carcinomas. METHODS. To study chromosomal aberrations associated with development and p rogression of biliary tract carcinomas, the authors used comparative genomi c hybridization to examine 50 such carcinomas. RESULTS. Gains in part or in whole of chromosomes Iq, 8q, and 20q and losse s of 5q, 8p, 9p, and 18q were detected frequently in early stage (T1/T2 cla ssification) biliary tract carcinomas (greater than or equal to 40% of 19 e arly stage tumors), and they also were found in advanced stage (T3/T4 class ification) tumors. In particular, loss of 9p was the most frequently observ ed aberration in both early stage (15 of 19; 78%) and advanced stage tumors (21 of 31; 68%). The frequencies of gains of 7p12-p14 (P < 0.003), 7p21-pt er (P < 0.0071, and 7q31 (P < 0.01) differed significantly between biliary tract carcinoma with and without distant metastasis. Also, gains of 5p and 19q13 and loss of 6q14-q16 were more frequent,in tumors with lymph node met astasis than in those without it (P < 0.02). CONCLUSIONS. It is likely that loss of 9p is one of the genetic aberrations critical for the development of biliary tract carcinoma, whereas gains of 5p, 7p, 7q, and 19q and loss of 6q are considered later events associated w ith tumor progression and are thought to confer metastatic potential to bil iary tract carcinomas. (C) 2001 American Cancer Society.