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.
dog; breast cancer; neoplasm; DNA flow cytometry; immunohistochemistry
