Assessment of the Concentration of Endogenous Factors Regulating Angiogenesis, VASH-1 and VEGF-A, in the Blood Serum of Patients with Neuroendocrine Neoplasms

Abstract

Neuroendocrine neoplasms (NENs) constitute about 2% of all malignant neoplasms, and the angiogenesis process in these tumors is still of a great interest. Vasohibin-1 (VASH-1) is an angiogenesis inhibitor, while vascular endothelial growth factor A (VEGF-A) is one of the main factors promoting vascular formation. The subject of this study was to assess serum concentration of these factors in patients with diagnosed NEN and in control group. Methods. The study group consisted of 120 patients with diagnosed NENs, while the control group consisted of 69 healthy volunteers. The concentrations of VASH-1 and VEGF-A in serum were tested using the ELISA. We also analyzed the association of the concentration of these factors with demographic data (e.g., age and gender), body mass index (BMI), primary tumor location, histological grade, metastasis, clinical staging, selected biochemical parameters and markers of NENs, and information on smoking habits. Results. The mean concentration of VASH-1 was $218.8\pm 359.8$  pg/ml in the study group and $973.1\pm 1239.4$  pg/ml in the control group, that difference was statistically significant ( $p<0.05$ ). In the NEN group, the highest concentration of VASH-1 was in patients with pancreatic NENs in relation to NENs with different location of the primary tumor ( $p<0.05$ ). Negative correlation was found between the concentration of VASH-1 and serotonin ( $r_S=-0.19$ , $p<0.05$ ). No statistically significant differences were observed for VEGF-A ( $p=0.658$ ). Conclusions. Patients with NENs showed lower serum level of VASH-1 in comparison to healthy volunteers. The highest level of VASH-1 was observed in tumors localized in pancreas. This might reflect the relevant function of VASH-1 in NENs and requires further evaluation to further knowledge of angiogenesis in NENs. Furthermore, the serum concentration of VEGF-A showed no statistical differences and probably does not have diagnostic value in this group of patients.