Impact of Regional Metastasis on Survival for Patients with Nonfunctional Pancreatic Neuroendocrine Tumors: A Systematic Review

Controversy exists regarding the benefit of lymphadenectomy for nonfunctional pancreatic neuroendocrine tumors (NF-PNET). MEDLINE/PubMed, EMBASE, and the Cochrane Library were searched for studies of pancreatic neuroendocrine tumors (PNET) published between 1990 and 2021. Studies of functional PNET were excluded. Reported incidence of lymph node metastasis (LNM) and survival analysis of either disease-free survival (DFS) or overall survival (OS) were required for inclusion. Overall, 52 studies analyzing 24,608 PNET met the inclusion criteria. The reported LNM rate for NF-PNET ranged from 7 to 64