Comparative evaluation of angiogenesis in gastric adenocarcinoma by nestin and CD34.

Tumor angiogenesis has been shown to be important for growth and metastasis in human neoplasms. Angiogenesis is usually determined by immunohistochemical staining of tumor tissue using various antibodies specific for endothelial cells. CD34 has been the one most commonly used in studies of tumor angiogenesis. Nestin, a class VI intermediate filament protein, was reported to be a good angiogenic marker in animal models. The aim of the current study was to compare the predictive value of angiogenesis as determined by CD34 and nestin on the same group of patients with advanced gastric carcinomas and to evaluate the possibility of nestin being a newer, better angiogenesis marker. Immunohistochemical staining using antinestin polyclonal antibody and anti-CD34 monoclonal antibody was carried out on surgical specimens from 61 patients with advanced gastric adenocarcinomas. The sensitivity of each of the two antibodies was evaluated by microvessel density (MVD) measurement by counting vessels in three 200x fields of intense neovascularization ("hot spots") of invasive tumors using a digital image analyzer. Immunoreactivity for nestin and CD34 was seen in the endothelial cells, and no stain was noted in the negative controls. MVD determined by nestin [87.74 +/- 29.30 (mean +/- standard deviation)] staining was significantly greater than that obtained by CD34 (82.48 +/- 32.27), and the difference was statistically significant. There was no correlation between MVD and patient clinical outcome with either antibody. Interestingly, in patients with larger carcinomas, MVD determined by nestin correlated better with longer survival than CD34. The difference was statistically significant. These results indicate that nestin is the better marker to evaluate neovascularity in endothelial cells. Evaluation of MVD determined by immunohistochemistry has limited value in patients with gastric carcinomas.