FLOW CYTOMETRIC ANALYSIS OF CELLULAR DNA CONTENT IN PARAFFIN WAX-EMBEDDED SPECIMENS OF CANINE MAMMARY-TUMORS

Flow cytometric analysis of DNA content was performed on 72 formalin-fixed, paraffin wax-embedded samples of canine mammary tumours. DNA content was correlated with histological appearance, stage of the tumour, and survival after mastectomy. All benign tumours (14 cases) were diploid. Amongst the malignant tumours, a higher incidence of aneuploid tumours (50 per cent) was observed in cases with lymph nodal metastases in comparison with those without metastases (26 per cent). All dogs with benign tumours survived for at least two years after mastectomy and so did 26 (81 per cent) of 32 DNA diploid malignant cases without metastases. A 67 per cent (eight of 12 cases) survival rate was found in the dogs with DNA aneuploid malignant tumours without metastases, while a very low survival rate (17 per cent) was observed in the group with malignant tumours with metastases, independently of the extent of p[oidy. © 1991, Academic Press Limited. All rights reserved.