title: Gastroenteric neuroendocrine neoplasms classification: comparison of prognostic models.
abstract: BACKGROUND
  Gastroenteric neuroendocrine neoplasms (GE-NENs) display highly variable clinical behavior. In an attempt to assess a better prognostic description, in 2010, the World Health Organization (WHO) updated its previous classification, and the European Neuroendocrine Tumors Society (ENETS) proposed a new grading and TNM-based staging system. In the current study, the authors evaluated the prognostic significance of these models and compared their efficacy in describing patients' long-term survival to assess the best prognostic model currently available for clinicians.
  
  
  METHODS
  The study cohort was composed of 145 patients with extrapancreatic GE-NEN who were observed from 1986 to 2008 at a single center and were classified according to the WHO and ENETS classifications. Survival evaluations were performed using Kaplan-Meyer analyses on 131 patients. Only deaths from neoplasia were considered. A P value < .05 was considered significant. Prognostic efficacy was assessed by determining the Harrell concordance index (c-index).
  
  
  RESULTS
  Both the 2010 WHO and the ENETS classification were able to efficiently divide patients into classes with different prognoses. According to the model comparison, the ENETS TNM-based staging system appeared to be the strongest. All combined models were effective prognostic predictors, but the model that included the 2010 WHO classification plus ENETS staging had a higher c-index.
  
  
  CONCLUSIONS
  Both the 2010 WHO classification and the ENETS staging system are valid instruments for GE-NENs prognostic assessment, with TNM-based stage appearing to be the best available choice for clinicians, both alone and in association with other classifications.
authors: Department of Endocrinology and Internal Medicine, Endocrine Tumors Unit, San Raffaele Scientific Institute, Milan, Italy.
authors: Anna
authors: A
authors: Dolcetta-Capuzzo
authors: Valentina
authors: V
authors: Villa
authors: Luca
authors: L
authors: Albarello
authors: Giulia M
authors: GM
authors: Franchi
authors: Marco
authors: M
authors: Gemma
authors: Marina
authors: M
authors: Scavini
authors: Saverio
authors: S
authors: Di Palo
authors: Elena
authors: E
authors: Orsenigo
authors: Emanuele
authors: E
authors: Bosi
authors: Claudio
authors: C
authors: Doglioni
authors: Marco F
authors: MF
authors: Manzoni
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000145:classification* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000145:classification* / Q000473:pathology; D011379:Prognosis; D016019:Survival Analysis