Microvessel density, VEGF expression, and tumor-associated macrophages in breast tumors: correlations with prognostic parameters.

Angiogenesis plays an important role in tumor growth, metastasis, and prognosis. Vascular endothelial growth factor (VEGF) is a potent endothelial mitogen and acts on the angiogenic stimulation of human neoplasias. In infiltrative ductal carcinoma (IDC), VEGF expression is correlated with high vascularity. Tumor-associated macrophages (TAMs) contribute to tumor proliferation, progression and angiogenesis and have a complex role in tumor biology. In this study, the correlations between microvessel density (MVD), VEGF expression, and TAMs and their relations to clinicopathological parameters such as tumor size, metastatic lymph node, mitotic activity index (MAI) and tumor grade were investigated in 48 cases of IDC and 30 infiltrative lobular carcinoma (ILC) cases. MVD showed a significant positive correlation with TAMs, VEGF, metastatic lymph nodes, tumor size and grade in IDC (P < 0.001). In ILC, MVD and tumor size were positively correlated (P = 0.003), while MVD was not correlated with VEGF, TAMs, MAI, metastatic lymph nodes, and grade. These findings are suggestive of angiogenesis stimulation in IDCs by VEGF, driving the macrophages into the tumor area. MVD and TAMs were found to be important prognostic factors in IDCs. On the other hand, however, VEGF did not contribute to angiogenesis in ILCs, and MVD and TAMs did not have any prognostic significance. These results suggest the involvement of factors not related to VEGF in the angiogenesis of lobular carcinoma.