Expression of TGF-alpha and EGFR in Breast Cancer and its Relation to Angiogenesis

Immunohistochemical analysis of the expression of transforming growth factor alpha (TGF-alpha) and its receptor, epidermal growth factor receptor (EGFR), was performed in a series of 86 invasive carcinomas of the breast. TGF-alpha immunostaining was observed in the majority of the cases (72.1%), both in epithelial cells and in adjacent stromal cells. EGFR was also present in tumors (34.2%) and in the endothelial cells (46.1% of the cases) near the tumors. A significant association was observed between TGF-alpha expression and angiogenesis evaluated by immunohistochemistry using an antibody against factor VIII-related antigen. No association was observed between TGF-alpha expression and other clinicopathologic features. In contrast, EGFR expression in the tumor was associated with features of poor prognosis, such as tumor size, histologic grade, lymph node status, estrogen receptor content, p53 expression, sialyl-Tn expression, and age. The presence of EGFR in endothelial cells was correlated to young patient age. We also observed an association of EGFR in endothelial cells and angiogenesis in tumors with a size of less than 2 cm. Inversely, in larger tumors, angiogenesis was only associated with tumor TGF-alpha expression. These results indicate that endothelial EGFR may play a role in the early steps of breast cancer angiogenesis.