Flow cytometric analysis of cellular DNA content in paraffin wax-embedded specimens of canine mammary tumours

DNA flow cytometry of canine mammary tumors: comparative aspects with human breast tumors

Flow cytometric analysis of DNA content was performed on 28 samples of canine mammary tumors. Nine of them were benign and 19 were malignant. All benign tumors and 11 malignant tumors (57.9%) were diploid (P<0.05). Form the aneuploid tumors, five (26.3%) were hyperdiploid, one (5.3%) hypodiploid, one (5.3%) near triploid and one (5.3%) multiploid. The analysis of the expression of the markers PR and CD31 revealed a significant difference between diploid and aneuploid tumors (P<0.05). The immunoreactivity of PR was higher in diploid tumors, while the immunoreactivity of CD31 was stronger in aneuploid tumors. No difference between the markers MIB-1, c-erbB2, p53 and Cyclin D1 was observed (P>0.05). Using the flow cytometry analysis and immunohistochemistry, it was found a close relationship between aneuploidy and malignant character of neoplasias, progesterone receptor (PR) negative immunostaining and higher microvases density. No correlation between DNA content and S phase or immunoreactivity for the markers MIB-1, p53, c-erbB2 and Cyclin D1 was observed.

Image analysis evaluation of ploidy, S-phase fraction and nuclear area in canine mammary tumours

Image analysis was used on cytocentrifuge preparations of Feulgen-stained nuclei extracted from formalin-fixed, paraffin wax-embedded tissues to determine ploidy (assessed by integrated optical density), S-phase fraction, and nuclear area of 90 canine mammary tumours (30 benign and 60 malignant). Only two lesions identified histologically as benign were aneuploid, suggesting potential malignancy. Of malignant tumours, 37% were aneuploid. No distinction based on ploidy could be made within benign or malignant groups, except for tubular adenocarcinomas of complex type, all of which were diploid. Mean S-phase fraction of malignant lesions (15.60%) was twice that of benign lesions (7.87%; P < 0.0001). The mean nuclear surface was significantly smaller in malignant lesions (70.62 microns2) than in benign counterparts (77.45 microns2; P < 0.05). No relation was found between a given tumour type and S-phase fraction or nuclear area within histologically malignant or benign tumour groups. Infiltration of lymphatics by neoplastic cells, known to indicate a poor prognosis, was associated with aneuploid lesions (mean DNA index > 1.25) and high S-phase fraction. The presence of necrosis and of a high number of mitoses was significantly associated with high S-phase fraction lesions.

DNA flow cytometry of canine mammary tumours: the relationship of DNA ploidy and S-phase fraction to clinical and histological features

The DNA ploidy status and S-phase fraction (SPF) of benign proliferative lesions (BPL) and malignant tumours (MT) in the mammary glands of dogs were determined by flow cytometric analysis and the results were related to their clinical and histological features. Seven (14.3 per cent) of 49 BPL and 16 (48.5 per cent) of 33 primary MT had aneuploid G0,1 peaks (P < 0.001). Hypodiploid G0,1 peaks were found in one BPL and in five primary MT. The DNA ploidy status of primary MT was not found to be associated with their size, nodal status, grade of histological malignancy or nuclear grade. In several cases there was intra-tumour heterogeneity in ploidy status independent of histological heterogeneity. The SPF was significantly higher in 27 primary MT than in 45 BPL when diploid and aneploid cases were combined for comparison (P < 0.05), but not when only diploid cases were compared. Among the primary MT the SPF was higher in aneuploid than in diploid tumours (P < 0.05) and it was higher in five MT from five dogs with regional disease than in 22 MT from 19 dogs with local disease (P < 0.05). The SPF was positively correlated with the grade of histological malignancy (P < 0.05) but not with nuclear grade.

Flow cytometric DNA ploidy analysis in canine transitional cell carcinoma of urinary bladders

Flow cytometric analysis of DNA ploidy was performed on 51 formalin-fixed, paraffin-embedded samples of canine transitional cell carcinoma of the urinary bladder. The DNA ploidy data obtained were compared to several clinicopathologic features. In addition, the DNA ploidy of 15 hyperplastic/inflamed and 8 normal canine urinary bladders was measured. Forty-three of the 51 neoplastic samples had interpretable DNA histograms. DNA aneuploidy was found in 34/43 (79%) of the transitional cell carcinoma samples. Of the 34 aneuploid neoplasms, 16 (47%) were hyperdiploid, 17 (50%) were tetraploid, and 1 (3%) was hypertetraploid. No significant correlation was found between the presence of DNA aneuploidy and the growth pattern, histologic grade, clinical stage, or individual morphologic features of this neoplasm. Additionally, the DNA ploidy was not related to the sex, age, or survival time of dogs with transitional cell carcinoma. All of the normal and all but one of the hyperplastic/inflamed urinary bladders were diploid. The results from this study demonstrated that DNA ploidy can be measured from paraffin-embedded canine samples by flow cytometry, a majority of the canine transitional cell carcinomas were aneuploid, and a significant correlation did not exist between the DNA ploidy and specific clinicopathologic features of this neoplasm.