Serum Angiogenic Factors in Patients with Neuroendocrine Tumors of Abdominal Organs

The initial (before treatment) levels of VEGF, endostatin, and tumor necrosis factor-β (TNF-β) were measured in the sera of 20 patients with malignant and benign neuroendocrine tumors of the abdominal organs and 25 healthy controls. The initial levels of VEGF, endostatin, and TNF-β in the total group of patients with neuroendocrine tumors of abdominal organs did not differ from the control. A signifi cant difference was detected between the mean serum concentrations of endostatin in patients with benign and malignant neuroendocrine tumors: 64.1±14.7 and 107.8±14.1 ng/ml, respectively (p=0.043). The content of VEGF, endostatin, and TNF-β did not correlate with patients' gender and age. A direct correlation between endostatin, TNF-β concentrations and maximum size of the primary tumor was detected in patients with malignant neuroendocrine tumors. Direct correlations between the initial levels of VEGF and endostatin and an inverse correlation between VEGF and TNF-β concentrations were detected in patients with benign neuroendocrine tumors. Relapse-free survival was signifi cantly lower in patients with serum endostatin concentration >100 ng/ml and TNF-β