The process of angiogenesis is a prerequisite for normal cell growth and differentiation. Neovascularization might also be important for tumor growth in the host tissue and for the establishment of growth in distant target tissue. Many studies
have
suggested that the presence of neovascularization (microvessel density) can be used as a "biologic marker" for the prediction of subsequent metastasis or mortality in breast cancer patients.
To evaluate the relationship between microvessel density and other known prognostic indicators in breast carinoma, we performed immunoperoxidase staining using CD31 (JC70, Dako) on 80 cases of formalin fixed human breast cancer tissue, and
counted
microvessel density(MVD) per x100 field in the most active areas of neovascularization. Also mammary tumors were experimentally induced by feeding of 9, 10-dimethyl-1, 2-benzan-thracene (DMBA) to female Sprague-Dawley rats, and then the
angiogenic
activity was observed during neoplastic transformation by immunoperoxidase staining for factor VIL-related antigen.
The mean value of MVD was 78.70±23.95 in the node negative group, and 91.23±26.18 in the node positive group. Thus there was a significant (p=0.0285) association of MVD with axillary nodal status. However, there was no association between MVD
and
other prognostic factors, i.e. estrogen and progesterone receptors, age, tumor size, and nuclear grade. Multivariate analysis by Cox's proportional hazard model disclosed that MVD, age of patients, axillary nodal status and nuclear grade could
influence
patient's prognosis.
Breast masses developed in 68% (25/37) of DMBA treated rate, and revealed fibro-adenomatous hyperplasia, adenomatous hyperplasia (hyperplastic alveolar nodule) and adenocarcinoma with increased neovascularization depending on size ad duration.
This
study concludes that the breast masses in DMBA treated rats can be used as an experimental animal model of neoangiogenesis in breast cancer.
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