Nestin-positive microvessel density is an independent prognostic factor in breast cancer

The process of angiogenesis based on new vessel formation within the tumour area plays a significant role in the progression of breast cancer. Nestin is an intermediate filament protein and participates in the cytoskeleton organization. Nestin expression in the endothelium of blood vessels is mainly limited to newly forming vessels, thus being a more specific marker of angiogenesis than the commonly used vascular antigens. The aim of this study was to determine the prognostic value of nestin-positive microvessel density (Nes(+)MVD) in breast cancer patients and to confirm that nestin expression is related to newly forming tumour vessels. In this study, 137 cases of ductal breast carcinoma and 19 cases of non-malignant breast tissue lesions (NBTLs) were examined. Immunohistochemical reactions were performed on paraffin sections using antibodies against nestin, CD34 and CD31 antigens. For each marker, the microvessel density (MVD) was determined. Nestin expression was also examined in human endothelial cell lines (HUVEC-SVT, HMEC-1 and HEPC-CB.1) representing a different level of endothelial cell maturity. HUVEC-SVT and HMEC-1 cells represent the endothelium of mature vessels, whereas HEPC-CB.1 cells represent the early endothelial progenitor cells (EPCs). We have demonstrated that high Nes+MVD may be associated with a more aggressive course of the disease and a poorer prognosis. We have also found a higher Nes+MVD in the cases with lymph node metastases, with higher histological grade, with advanced-stage disease and with the triple-negative (TN) breast cancer. In addition, nestin expression in vessels was associated with a shorter overall survival (OS) and earlier relapse, and in the case of OS nestin was an independent prognostic factor. Finally, we further confirmed that nestin expression in endothelial cells reflects a progenitor nature of newly forming vessels.