Endocan has been reported as specific of endothelial tumor cells and was shown to be expressed by tip cells during angiogenesis process.
The principal aims of the study are the assessment of immunohistochemical VEGF and Endocan expression in functioning and non functioning pNETs and the comparison of these markers with clinical features, Ki67 and TNM staging.
We collected a total number of 79 pNETs surgical specimens for immunohistochemestry (IHC). The population chosen has been classified according to type of diagnosis, sex, age, grading and staging.
We report the preliminary results of IHC for VEGF and Endocan performed on 46 patients. The expression of Endocan is limited to endothelial cells within neoplastic tissue. VEGF is expressed in the cytoplasm of tumoral cells. VEGF and Endocan expression is strictly connected, considering that Endocan expression upon endothelial cells is stimulated by VEGF production by neoplastic cells (P <0,001). The grading is directly correlated to the stage and in our series this finding is confirmed (P 0.001). We correlated Endocan and VEGF expression to Ki67 and TNM classification. We found a significant correlation between Endocan and VEGF expression and metastatic disease (P 0.005 and <0.001 respectively).
These preliminary data seem to show that Endocan and VEGF immunohistochemical expression in pNETs may be predictive markers of aggressiveness.