Clinicopathologic study of neovascularization and VEGF expression in superficial esophageal carcinoma

Among superficial esophageal carcinomas (SECs), mucosal carcinoma (m) and submucosal carcinoma (sm) markedly differ regarding the presence or absence of lymph node metastases and long-term survival. To clarify differences in the growth pattern of these two superficial carcinomas, we investigated neovascularization around the site of tumor growth and expression of vascular endothelial growth factor (VEGF) in tumor cells, in patients undergoing radical esophagectomy or endoscopic mucosal resection (EMR). Moreover, we investigated whether these factors were related to the prognosis in patients undergoing treatment of SEC. This study included 90 SEC patients undergoing radical esophagectomy (surgery group) and 35 patients undergoing EMR (EMR group). For immunohistochemical staining antibodies against factor VIII-related antigen and against VEGF were used. The microvessels around the tumor were counted to calculate the vascular index (VI). VI and VEGF expression in the tumor were compared in relation to clinicopathologic findings. In the surgery group, the VI and the percent of VEGF-positive cells were significantly higher in the case of sm carcinomas. Furthermore, tumors with a high VI showed a significantly worse prognosis. In the EMR group, the VI and percent of VEGF-positive cells increased with the depth of the tumor. The VI and VEGF expression were significantly higher in sm carcinomas. This may in part explain the difference in cancer progression between m and sm carcinomas. In patients undergoing resection or EMR, examination of neovascularization using VI may be potentially useful in evaluating the prognosis of SEC.