title: Prognostic factors and characteristics of pancreatic neuroendocrine tumors: single center experience.
abstract: OBJECTIVE
  Pancreatic neuroendocrine tumors (PNET) are a rare subgroup of tumors. For PNETs, the predictive factors for survival and prognosis are not well known. The purpose of our study was to evaluate the predictive factors for survival and disease progression in PNETs.
  
  
  METHODS
  We retrospectively analyzed 37 patients who were diagnosed with PNET at Severance Hospital between November 2005 and March 2010. Prognostic factors for survival and disease progression were evaluated using the Kaplan-Meier method.
  
  
  RESULTS
  The mean age of the patients was 50.0±15.0 years. Eight cases (21.6%) were described as functioning tumors and 29 cases (78.4%) as non-functioning tumors. In univariate analysis of clinical factors, patients with liver metastasis (p=0.002), without resection of primary tumors (p=0.002), or American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) stage III/IV (p=0.002) were more likely to demonstrate shorter overall survival (OS). Patients with bile duct or pancreatic duct invasion (p=0.031), sized-lesions larger than 20 mm (p=0.036), liver metastasis (p=0.020), distant metastasis (p=0.005), lymph node metastasis (p=0.009) or without resection of primary tumors (p=0.020) were more likely to demonstrate shorter progression-free survival (PFS). In multivariate analysis of clinical factors, bile duct or pancreatic duct invasion [p=0.010, hazard ratio (HR)=95.046] and tumor location (non-head of pancreas) (p=0.036, HR=7.381) were confirmed as independent factors for predicting shorter PFS.
  
  
  CONCLUSIONS
  Patients with liver metastasis or without resection of primary tumors were more likely to demonstrate shorter OS. Patients with bile duct or pancreatic duct invasion or tumors located at body or tail of pancreas were more likely to demonstrate shorter PFS.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul 120-752, Korea.
authors.forename: Tak Geun
authors.initials: TG
authors.lastname: Oh
authors.forename: Moon Jae
authors.initials: MJ
authors.lastname: Chung
authors.forename: Jeong Yeop
authors.initials: JY
authors.lastname: Park
authors.forename: Seung Min
authors.initials: SM
authors.lastname: Bang
authors.forename: Seung Woo
authors.initials: SW
authors.lastname: Park
authors.forename: Jae Bok
authors.initials: JB
authors.lastname: Chung
authors.forename: Si Young
authors.initials: SY
authors.lastname: Song
mesh_terms: D000328:Adult; D000368:Aged; D001650:Bile Duct Neoplasms / Q000556:secondary; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000150:complications / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000150:complications / Q000473:pathology*; D012189:Retrospective Studies