title: A simplified prognostic system for resected pancreatic neuroendocrine neoplasms.
abstract: BACKGROUND
  A number of prognostically relevant clinicopathological variables have been proposed for pancreatic neuroendocrine neoplasms. However, a standardized prognostication system has yet to be established for patients undergoing potentially curative tumour resection.
  
  
  METHODS
  We examined a prospectively maintained, single-institution database to identify patients who underwent potentially curative resection of non-metastatic primary pancreatic neuroendocrine neoplasms. Patient, operative and pathological characteristics were analysed to identify variables associated with disease-specific and disease-free survival.
  
  
  RESULTS
  Between 1991 and 2007, 43 patients met inclusion criteria. After a median follow-up of 68 months, 5-year disease-specific survival was 94% and 5-year disease-free survival was 72%. Tumours sized > or = 5 cm and vascular invasion were associated with worse disease-specific survival. Tumours sized > or = 5 cm, nodal metastases, positive resection margins and perineural invasion were associated with worse disease-free survival. A scoring system consisting of tumour size > or = 5 cm, histological grade, nodal metastases and resection margin positivity (SGNM) permitted stratification of disease-specific (P= 0.006) and disease-free (P= 0.0004) survival. This proposed scoring system demonstrated excellent discrimination of individual disease-specific and disease-free survival outcomes as reflected by concordance indices of 0.814 and 0.794, respectively.
  
  
  CONCLUSIONS
  A simple scoring system utilizing tumour size, histological grade, nodal metastases and resection margin status can be used to stratify outcomes in patients undergoing resection of primary pancreatic neuroendocrine neoplasms.
authors.affiliation: Section of Surgical Oncology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792-7375, USA.
authors.forename: Nikiforos
authors.initials: N
authors.lastname: Ballian
authors.forename: Agnes G
authors.initials: AG
authors.lastname: Loeffler
authors.forename: Victoria
authors.initials: V
authors.lastname: Rajamanickam
authors.forename: Peter A
authors.initials: PA
authors.lastname: Norstedt
authors.forename: Sharon M
authors.initials: SM
authors.lastname: Weber
authors.forename: Clifford S
authors.initials: CS
authors.lastname: Cho