Well-differentiated grade 1 and 2 nonfunctioning pancreatic neuroendocrine tumor: Consideration of additional factors to aid treatment decision-making.

BackgroundGuidelines for 1-2 ​cm well-differentiated non-functional pancreatic neuroendocrine tumors (NF-PNET) are broad; observation (OB), enucleation (EN), and pancreatic resection (PR) all viable. The objective is analyzing factors impacting survival between approaches.MethodsRetrospective analysis of NCDB for 1-2 ​cm well-differentiated grade 1/2 NF-PNET stratified by approach. Factors predicting survival analyzed using Cox regression.Results4023 patients included; 1030 OB, 321 ​EN, and 2672 ​PR. EN was associated with improved survival (HR 0.20, 95 %CI 0.08-0.53) and was dependent on negative margins (margin negative: HR 0.12, 95 %CI 0.05-0.34). Positive margins for EN were high (29.7 ​% EN vs. 3.4 ​% PR, p ​< ​0.01). Factors influencing margins for EN were pancreatic tail location (OR 0.36, 95 %CI 0.13-0.98) and lymphovascular invasion (OR 5.28, 95 %CI 1.42-19.53). Among PRs, only distal pancreatectomy conferred improved survival (HR 0.53, 95 %CI 0.30-0.92).ConclusionOptimal treatment for 1-2 ​cm well-differentiated NF-PNET should incorporate factors influencing positive margins for EN and resection type for PR.