title: Malignant-functioning neuroendocrine tumors of the pancreas: A survival analysis.
abstract: BACKGROUND
  Malignant-functioning pancreatic neuroendocrine tumors (mFpNETs) are rare. Research analyzing the presentation, biological behavior, and patient outcomes of these tumors is limited.
  
  
  METHODS
  We used the Surveillance, Epidemiology, and End Results database to identify patients with malignant insulinomas, gastrinomas, glucagonomas, vasoactive intestinal peptide secreting tumors (VIPomas), somastatinomas, and mixed islet cell tumors (MICTs). The primary endpoint of this study was to identify factors affecting survival.
  
  
  RESULTS
  We identified 401 patients with mFpNETs. Between histologic subtypes, there were significant differences in sex and age, and in tumor size, grade, location, and stage. Median survival time for insulinomas was 12.7 years; gastrinomas, 10.2 years; glucagonomas, 7.7 years; VIPomas, 7.9 years; and MICTs, 3.4 years. Multivariable analysis showed that histology (insulinoma, gastrinoma, and VIPoma; P = .009), absence of distant metastases (P = .002), age < 50 years (P = .001), surgical intervention (P = .001), and stage I/II disease (P = .011) were independently associated with prolonged survival. Subgroup analysis demonstrated that removal of the primary tumor in stage IV mFpNETs was associated with significantly prolonged survival (P = .01).
  
  
  CONCLUSIONS
  mFpNETs are rare tumors that commonly present at an advanced stage despite hormonal secretion. Primary tumor resection is associated with longer survival in stages I-III as well as stage IV tumors.
authors.affiliation: Endocrine Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD. Electronic address: xavier.keutgen@nih.gov.
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: Electron
authors.initials: E
authors.lastname: Kebebew
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018273:Carcinoma, Islet Cell / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007340:Insulinoma / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies; D018426:SEER Program; D016019:Survival Analysis; D014481:United States / Q000453:epidemiology