INTERPHASE CYTOGENETIC ANALYSIS OF ERBB2 AND TOPOII-ALPHA COAMPLIFICATION IN INVASIVE BREAST-CANCER AND POLYSOMY OF CHROMOSOME-17 IN DUCTALCARCINOMA IN-SITU

Breast cancer is a genetically complex disease. Fluorescence in situ h ybridisation can be used to analyse the genetics of breast-cancer prog ression by interphase cytogenetics. We have analysed the histological distribution of erbB2 and topoll alpha co-amplification in paraffin se ctions of invasive breast cancer and show that the co-amplified loci s hare the same histological distribution in the tumour and have a simil ar nuclear distribution within individual nuclei. Regions of the tumou rs without amplification are easily recognized and tumours with erbB2 and topoll alpha co-amplification can be distinguished from those with erbB2 amplification alone. In addition, FISH was used to show polysom y of chromosome 17 in non-invasive ductal carcinoma in situ of the bre ast and erbB2 amplification in both the invasive and non-invasive comp onents of a breast cancer biopsy. This report of an interphase cytogen etic analysis of non-invasive breast carcinoma in situ demonstrates th e usefulness of FISH for the genetic study of breast cancer progressio n. (C) 1995 Wiley-Liss, Inc.