Management of early gastrointestinal neuroendocrine neoplasms

Table 6 Therapy of duodenal NENs

Type	≤1 cma	1-2 cma	Any size but risk factorsb
Sporadic NET (no gastrinoma, no MEN1 )	EMR	Surgery (in case of surgical risk: EMR followed by surveillance)	Surgery
Sporadic gastrinoma	Surgeryc	Surgeryc	Surgeryc
Gastrinoma and MEN1	PPI therapy and surveillance (or surgery)	Surgery (particularly if the gastrinoma is growing) or PPI therapy combined with surveillance	Surgery (or PPI therapy combined with surveillance in G1 gastrinomas and/or surgical risk)
NEC (G3)	-	-	Surgery or cytoreductive chemotherapy

^awithout risk factors (for metastatic disease) such as G2-G3, angioinvasion, infiltration of the muscularis propria or tumor size > 2 cm;

^bin the presence of risk factors for metastatic disease, surgery is generally indicated, regardless of tumor size;

^cSurgery is the therapy of choice for sporadic gastrinoma (without distant metastases). In (very) elderly patients conservative management may, however, be preferred to surgery. Adjuvant (medical) therapy is not established in NET/carcinoid disease. NET: Well differentiated neuroendocrine tumor; EMR: Endoscopic mucosal resection; PPI: Proton pump inhibitor; MEN1: Multiple endocrine neoplasia type 1.