Small bowel neuroendocrine tumors: From pathophysiology to clinical approach

Table 1 Duodenal neuroendocrine tumors treatment

Duodenal NETs – surgical treatment
≤ 1 cm	Local ressection (if possible)
≥ 2 cm OR lymph nodes metastasis	Surgical ressection
Potentially resectable hepatic metastases without distant metastases and no other significant comorbility	Palliative surgery
Duodenal NETs – farmacological treatment
Functional duodenal NETs	Hormone suppression treatment
Well-differentiated NETs	Systemic chemotherapy if advanced metastatic disease
Poorly differentiated tumors	Combination chemotherapy – variable duration disease remission
	mTOR, tyrosine kinase and VEGF inhibitors – phase 3 trials with promising results
Metastatic or inoperable disease	Peptide receptor radionuclide therapy
	When all other treatment options fail
	If positive octreoscan

NETs: Neuroendocrine tumors; VEGF: Vascular endothelial growth factor.

Table 2 Jejunal and ileal neuroendocrine tumors treatment

Jejunal and ileal NETs – surgical treatment
Without metastasis, all sizes	Surgical resection with wide lymphadenectomy + search for other lesions
With liver metastases	Attempt curative surgery; intraoperative ultrasonography should be performed for detection of all liver metastases
	If patient not suitable for curative resection, palliative surgery should be considered to prevent complications attributable to the tumor mass
Jejunal and ileal NETs – farmacological treatment
Functional jejunal-ileal NETs	1st line: Somatostatin analogs (symptomatic treatment and tumor growth stabilization)
	2nd line: Interferon-α
Well-differentiated NETs	Systemic chemotherapy not recommended
Poorly differentiated tumors	Combination chemotherapy – variable duration disease remission
	mTOR, tyrosine kinase and VEGF inhibitors – phase 3 trials with promising results
Metastatic or inoperable disease	Peptide receptor radionuclide therapy
	When all other treatment options fail
	If positive Octreoscan

NETs: Neuroendocrine tumors; VEGF: Vascular endothelial growth factor.