COMPUTER-ASSISTED IMAGE-ANALYSIS OF INTRATUMORAL VESSEL DENSITY IN MAMMARY-TUMORS FROM DOGS

Objective-To determine whether intratumoral microvessel density can be used to distinguish benign from malignant mammary tumors in dogs and to predict the outcome of surgical treatment for small volume (< 3-cm diameter) tumors. Sample Population-Tissue sections from 58 mammary tu mors (42 malignant and 16 benign) from dogs. Procedure-Mammary tumors were stained by immunohistochemistry for factor VIII-related antigen. Computer-assisted image analysis was used to determine intratumoral ve ssel density in immunostained areas. Total vascular density (TVD), cal culated from 3 non-overlapping fields, was analyzed for correlation wi th patient or tumor histomorphologic characteristics, and results obta ined by surgical treatment of small volume tumors. Results-Mean TVD of malignant tumors was significantly greater than that of benign tumors . Total Vascular density was not correlated with patient age, sex, rep roductive status, clinical tumor stage, or histologic type. For small volume (< 3-cm diameter) malignant tumors, mean TVD was higher in tumo rs that recurred after surgery than in tumors that did not recur; howe ver, TVD was not predictive of time to recurrence. Conclusion and Clin ical Implications-Immunohistochemistry and computer-assisted image ana lysis allowed objective quantitation of intratumoral microvessel densi ty in formalin-fixed, paraffin-embedded tissue sections. Tumors with h igh TVD were more likely to recur after surgical treatment than tumors with low TVD suggesting that TVD measurements can be used by the clin ician, in addition to histologic type and clinical stage, to predict p rognosis after surgical treatment. These data also provide rationale f or use of antiangiogenesis strategies for treatment of malignant mamma ry tumors in dogs.