Angiogenic markers endoglin and vascular endothelial growth factor in gastroenteropancreatic neuroendocrine tumors

Table 2 Mean endoglin and vascular endothelial growth factor levels in gastroenteropancreatic neuroendocrine tumors in relation to clinicopathological parameters

	Endoglin (ng/mg)				VEGF (pg/mg)
	n	mean	SE	P	n	mean	SE	P
Tissues
Normal	38	12.1	2.0	< 0.012	38	75.0	9.5	< 0.012
Tumor	27	26.8	4.5		26	316.8	46.0
Tumor type
Carcinoid	8	35.3	11.4	0.37	8	354.9	72.0	0.67
Functional PNET	14	25.4	4.7		13	274.4	46.7
Non-functional PNET	5	16.8	8.7		5	366.2	186.8
Origin
Primary tumors	19	18.8	3.9	< 0.012	18	293.2	52.0	0.45
Metastatic tumors	8	45.7	9.0		8	369.9	95.8
WHO classification
Well-differentiated NETs	6	7.6	5.2	0.0212	6	200.2	52.8	0.211
Well-differentiated NECs	20	32.9	4.0		19	328.5	60.2
Poorly-differentiated NECs	1	19.0	ND		1	795.0	ND
Primary tumors: metastases
Present	12	24.8	5.2	0.042	11	339.5	76.4	0.28
Absent	7	8.5	3.5		7	220.6	54.8

¹Result of unpaired t test to compare well-differentiated neuroendocrine tumors (NETs) with well-differentiated neuroendocrine carcinomas (NECs);

²P values are considered statistically significant. VEGF: Vascular endothelial growth factor; PNET: Pancreatic neuroendocrine tumor; ND: Not described.