title: Resection of primary tumor site is associated with prolonged survival in metastatic nonfunctioning pancreatic neuroendocrine tumors.
abstract: BACKGROUND
  Nonfunctioning pancreatic neuroendocrine tumors (NFpNET) present with distant metastases in up to 50% of patients. It is unknown whether removal of the primary tumor in patients with NFpNET and metastases is beneficial.
  
  
  METHODS
  We used the Surveillance, Epidemiology, and End Results database to identify patients with NFpNET and distant metastases. The primary outcome measure in this study was overall survival.
  
  
  RESULTS
  We identified 882 patients with metastatic NFpNET who had survival data; 303 (34%) patients had operative removal of their primary tumor of which 243 (80%) were grade I or II. Median survival of patients undergoing resection of the primary site was 65 (95% confidence interval 60-86) versus 10 (8-12) months for those without resection (P < .0001). Patients diagnosed after 2003 (n = 625, 71%) were more likely to undergo an operation than those diagnosed earlier (P = .001). Multivariable analysis showed that a lesser tumor grade (P < .0001), younger age (P < .0001), diagnosis during or after 2003 (P = .0003), tumor site in the body/tail (P = .009), and operative resection of the primary tumor site (P < .0001) were associated with prolonged survival of patients with NFpNET and distant metastases.
  
  
  CONCLUSIONS
  This study suggests that resection of the site of the primary NFpNET is associated with greater survival in patients with distant metastases and could therefore be considered as a additional treatment option in this patient population.
authors.affiliation: Endocrine Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD.
authors.forename: Xavier M
authors.initials: XM
authors.lastname: Keutgen
authors.affiliation: Endocrine Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD.
authors.forename: Naris
authors.initials: N
authors.lastname: Nilubol
authors.affiliation: Endocrine Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD.
authors.forename: Joanne
authors.initials: J
authors.lastname: Glanville
authors.affiliation: Endocrine Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD.
authors.forename: Samira M
authors.initials: SM
authors.lastname: Sadowski
authors.affiliation: Biostatistics and Data Management Section, Office of the Clinical Director, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD.
authors.forename: David J
authors.initials: DJ
authors.lastname: Liewehr
authors.affiliation: Biostatistics and Data Management Section, Office of the Clinical Director, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD.
authors.forename: David J
authors.initials: DJ
authors.lastname: Venzon
authors.affiliation: Biostatistics and Data Management Section, Office of the Clinical Director, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD.
authors.forename: Seth M
authors.initials: SM
authors.lastname: Steinberg
authors.affiliation: Endocrine Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD. Electronic address: kebebewe@mail.nih.gov.
authors.forename: Electron
authors.initials: E
authors.lastname: Kebebew
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000473:pathology / Q000556:secondary / Q000601:surgery*; D010179:Pancreas / Q000601:surgery*; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000473:pathology / Q000556:secondary / Q000601:surgery*; D018426:SEER Program; D016019:Survival Analysis; D014481:United States