title: Evaluation of the WHO 2010 grading and AJCC/UICC staging systems in prognostic behavior of intestinal neuroendocrine tumors.
abstract: BACKGROUND
  The increasing incidence and heterogeneous behavior of intestinal neuroendocrine tumors (iNETs) pose a clinicopathological challenge. Our goal was to decribe the prognostic value of the new WHO 2010 grading and the AJCC/UICC TNM staging systems for iNETs. Moreover, outcomes of patients treated with somatostatin analogs were assessed.
  
  
  METHODS
  We collected epidemiological and clinicopathological data from 93 patients with histologically proven iNETs including progression and survival outcomes. The WHO 2010 grading and the AJCC/UICC TNM staging systems were applied for all cases. RECIST criteria were used to define progression. Kaplan-Meier analyses for progression free survival (PFS) and overall survival (OS) were performed.
  
  
  RESULTS
  Mean follow-up was 58.6 months (4-213 months). WHO 2010 grading yielded PFS and disease-specific OS of 125.0 and 165.8 months for grade 1 (G1), 100.0 and 144.2 months for G2 and 15.0 and 15.8 months for G3 tumors (p = 0.004 and p = 0.001). Using AJCC staging, patients with stage I and II tumors had no progression and no deaths. Stage III and IV patients demonstrated PFS of 138.4 and 84.7 months (p = 0.003) and disease-specific OS of 210.0 and 112.8 months (p = 0.017). AJCC staging also provided informative PFS (91.2 vs. 50.0 months, p = 0.004) and OS (112.3 vs. 80.0 months, p = 0.005) measures with somatostatin analog use in stage IV patients.
  
  
  CONCLUSIONS
  Our findings underscore the complementarity of WHO 2010 and AJCC classifications in providing better estimates of iNETS disease outcomes and extend the evidence for somatostatin analog benefit in patients with metastatic disease.
authors.affiliation: Department of Medicine, University Health Network, Toronto, Ontario, Canada.
authors.forename: Paula B
authors.initials: PB
authors.lastname: Araujo
authors.forename: Sonia
authors.initials: S
authors.lastname: Cheng
authors.forename: Ozgur
authors.initials: O
authors.lastname: Mete
authors.forename: Stefano
authors.initials: S
authors.lastname: Serra
authors.forename: Emilie
authors.initials: E
authors.lastname: Morin
authors.forename: Sylvia L
authors.initials: SL
authors.lastname: Asa
authors.forename: Shereen
authors.initials: S
authors.lastname: Ezzat
mesh_terms: D005260:Female; D006801:Humans; D007414:Intestinal Neoplasms / Q000188:drug therapy / Q000473:pathology*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000188:drug therapy / Q000473:pathology*; D011379:Prognosis; D013004:Somatostatin / Q000031:analogs & derivatives / Q000627:therapeutic use; D014944:World Health Organization
chemical_list: D013004:Somatostatin; C081788:pentetreotide