L'angiogenesi nel carcinoma della mammella

Angiogenesis, the development of new blood vessels, is essential for tumour growth, and metastatic spread. Microvessel density (MVD) of breast cancer is widely regarded as a prognostic factor, but the results from other studies have produced conflicting results. The present study was performed in order to define the prognostic value of MVD on a series of 378 node-negative breast cancer patients. Microvessels were stained using Factor-VIII antibody. MVD was determined independently by 2 observers according to Weidner's method. In parallel, cell proliferation, oestrogen and progesterone receptors were evaluated. Tumour MVD varied greatly from tumour to tumour (2 to 232 MV/mm²) and was unrelated to patient age and menopausal status, or to tumour size, histology and receptor status. A significant (p = 0.004) but inverse correlation (r_s = -0.188) was observed with cell proliferation. Univariate analysis, using 40 MV/mm² as cut-off, showed an inverse relation with 5-year relapse-free survival rate (82% vs 71%, p = 0.018). This finding was limited to very small, slowly proliferating and ER-negative tumours. Multivariate analysis identified tumour size and TLI, as independent prognostic factors. Therefore, on the basis of our results, angiogenesis does not seem to have an independent prognostic value.