Correlations between vascular endothelial growth factor expression, microvascular density in tumor tissues and TNM staging in breast cancer

Breast cancer is the most frequent malignancy in women worldwide. In spite of its questionable reliability, the TNM (Tumor, Node, Metastasis) staging system is widely used for the prognosis of this disease. On the other hand, angiogenesis is considered to have an essential role in the evolution of breast cancer and the Vascular Endothelial Growth Factor (VEGF) has proven to be the key regulator of this process. Quantitation of VEGF and the tumor vasculature might play an important role in predicting tumor behavior and patient management. The aim of our study was to evaluate the potential correlation between the VEGF expression, microvessel density (MVD) in the tumor tissues and TNM staging in breast cancer. We included 34 patients with breast cancer who had undergone surgical treatment and evaluated each case clinically, histopathologically and by immunohistochemistry for VEGF and CD31 expression in the tumor tissues. VEGF expression was evaluated by calculating the average percentage of cytoplasmic positive cells from 3 high power fields. MVD was expressed as the average number of the CD31+ microvessels from 3 high power fields. Expression of VEGF was significantly associated with the number of lymph nodes with metastasis, the number of cells in mitosis, the presence of necrosis and the T-stage (inverse correlation). MVD correlated very well with the histological grading, the number of cells in mitosis, the presence of inflammation and the presence of necrosis. No correlation could be established between VEGF expression and MVD. Although their relationship with TNM staging remains unclear, VEGF expression and MVD proved to be important indicators of the malignant status in breast cancer, confirming the major involvement of angiogenesis in this type of cancer. Both of them are valuable prognostic factors in breast cancer, but the pattern of their relationship needs further analysis of the VEGF receptors in order to be described.