Different patterns of chromosomal imbalances in metastasising and non-metastasising primary breast carcinomas

In an attempt to identify chromosomal abnormalities that may be associated with a metastatic phenotype, we investigated the pattern of chromosomal gai ns and losses in 66 node positive and 63 node-negative primary breast carci nomas. For both subgroups of tumours, losses were more common than gains an d the losses were most often the result of structural aberrations. The exce ptions were the long arm of chromosome I, and chromosomes 7, 8, 12, 18 and 20, which were more often gained than lost. Node-negative tumours were pref erentially characterised by loss of 6q10-21 and loss of 16q, whereas loss o f chromosome is was significant for node-positive tumours. Other aberration s that tended to be associated with one of the phenotypes, though not stati stically significant, were gain of chromosome 18 and loss of chromosome 10 in node-negative tumours, and gain of chromosome 14 and loss of 12p in node positive tumours. Our data show that there are differences among the genet ic lesions present in node-negative and node-positive breast tumours. Int. J. Cancer (Pred. Oncol.) 84:370-375, 1999. (C) 1999 Wiley-Liss, Inc.