Endoglin (CD105) and vascular endothelial growth factor as prognostic markers in esophageal adenocarcinoma

Endoglin (CD105), a member of transforming growth factor beta1 receptor complex, has been shown to be a more useful marker to identify tumor angiogenesis than panendothelial markers such as CD31. We investigated endoglin and vascular endothelial growth factor (VEGF) expression as possible prognostic markers in esophageal adenocarcinoma. Surgical specimens from 75 patients with esophageal adenocarcinoma treated with esophagectomy were immunostained for endoglin, CD31, and VEGF. We also included 10 cases of Barrett's esophagus with high-grade dysplasia and 10 cases with Barrett's esophagus low-grade dysplasia. Positively stained microvessels (MVs) were counted in hot spots at magnification of x400. Results were expressed as the highest number of MV identified. For VEGF, intensity of staining was scored on 3-tiered scale. Endoglin demonstrated significantly more vessels than the CD31 (mean, 28.9 +/- 13.2 versus 19.0 +/- 9.4, P < .001). Both endoglin and CD31 MV counts showed significant correlation with stage of the disease (r = 0.59, P < .001; r = 0.52, P < .001, respectively) and patient survival (log rank P < .01). Only endoglin MV count was significantly correlated with the presence of angiolymphatic invasion (r = 0.34, P < .05) and lymph node (LN) metastases (r = 0.48, P < .001). Univariate analysis showed that endoglin MV count is an independent prognostic factor. Endoglin showed a significant increase in MV count in Barrett's esophagus with high-grade dysplasia when compared with Barrett's esophagus low-grade dysplasia (P < .01), whereas CD31 did not show any significant difference. VEGF was expressed in 48 (64%) of 75 cases of adenocarcinoma and was significantly correlated with angiolymphatic invasion, LN metastases, and survival. In conclusion, endoglin is a specific and sensitive marker for tumor angiogenesis. Endoglin staining also showed prognostic significance with positive correlation with the presence of angiolymphatic invasion, LN metastases, tumor stage, and survival.