Histochemical study of vascular endothelial growth factor in squamous cell carcinoma of the esophagus

Vascular endothelial growth factor (VEGF) plays a key role in tumor angiogenesis. The aim of this study was to clarify the significance of VEGF expression in esophageal squamous cell carcinoma (SCC).

Tissues samples were taken from 52 patients with esophageal SCC after surgery. VEGF expression in these SCCs was examined immunohistochemically. Microvessels in the tumor stained for Factor VIII-related antigen were counted. Ki-67 antigen as a proliferative marker was immunostained with MIB-1, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end labeling was performed for the evaluation of apoptosis. Ki-67 labeling index (LI) and apoptotic index were then calculated.

VEGF expression was observed in 30 of the patients (57.7%). The microvessel count was significantly higher (p = 0.007), and the apoptotic index was significantly lower (p < 0.0001) in the SCC with VEGF expression than in the SCC without it, but no significant difference was observed in the Ki-67 LI between these groups. There was an inverse correlation between the microvessel count and the apoptotic index (p = 0.007). In the clinicopathologic factors, histologic venous invasion of cancer cells (p = 0.039) and lymph node metastasis (p = 0.049) were significantly correlated with VEGF expression. The survival rate after curative surgery was better in the patients without VEGF expression (p < 0.05), and distant organ metastasis after surgery was frequently observed in the patients with VEGF expression (p = 0.023).

These results suggest that VEGF expression is associated with angiogenesis in esophageal SCC, and may be a prognostic factor in patients with esophageal SCC. Furthermore, apoptosis may be influenced by angiogenesis in esophageal SCC.