Data from Prognostic Value of Tumor Architecture, Tumor-Associated Vascular Characteristics, and Expression of Angiogenic Molecules in Pancreatic Endocrine Tumors

Abstract

<div>Abstract<p><b>Purpose:</b> It is difficult to predict the biological behavior of pancreatic endocrine tumors (PETs). Our aim was to evaluate the prognostic significance of certain variables in PETs.</p><p><b>Experimental Design:</b> The following variables were examined in 37 patients with PETs and then compared with other clinicopathologic characteristics: histologic tumor structure; microvessel density (MVD) measured by three different methods, including a unique method involving calculation of solid area MVD; endothelial proliferation; and the immunohistochemical expression of vascular endothelial growth factor-A and CXC chemokine CXCL-12. Intratumoral vascular structures were analyzed by double immunofluorescence using 30-μm-thick sections.</p><p><b>Results:</b> The presence of focal and intensive solid growth of tumor cells (large solid nests; <i>P</i> = 0.003), low solid area MVD (<i>P</i> = 0.002), a high endothelial cell proliferation index (EPI; <i>P</i> = 0.005), and high expression of CXCL-12 in PET cells (<i>P</i> = 0.018) were significant unfavorable prognostic indicators. The predominant structure of the overall tumor histology and the expression of vascular endothelial growth factor-A did not separate aggressive PETs. In areas of focal solid growth, tumor-associated blood vessels had obviously low MVD and high EPI, and their structures were poorly formed with highly abnormal features, in comparison with other areas. High expression of CXCL-12 in tumor cells was significantly associated with variables representing tumor growth, hematogenous tumor spread, low MVD, high EPI, and the presence of large solid nests.</p><p><b>Conclusions:</b> This study has provided novel findings on the prognostic features of tumor architecture and tumor-associated angiogenesis in PETs. CXCL-12 is the first candidate molecule in association with neoangiogenesis in PETs.</p></div>