title: Comparative performances of the 7th and the 8th editions of the American Joint Committee on Cancer staging systems for intrahepatic cholangiocarcinoma.
abstract: BACKGROUND
  We sought to evaluate and validate the 8th edition of the AJCC classification using a multi-institutional cohort of patients with intrahepatic cholangiocarcinoma (ICC).
  
  
  METHODS
  Patients undergoing curative-intent hepatic resection for ICC between 1990 and 2015 at 14 major hepatobiliary centers were included and were staged according to 7th and 8th editions AJCC criteria.
  
  
  RESULTS
  A total of 1154 patients underwent liver resection for ICC. When patients were staged using the AJCC 7th edition, T2a, T2b, and T4 patients had a higher hazard ratio (HR) of death compared with T1 (T2a, HR 1.43, P = 0.004; T2b, HR 1.99, P < 0.001; T4, HR 2.20, P < 0.001). T3 patients had a higher HR of death compared with T1 patients (HR 1.30, P = 0.029) but lower than T2a and T2b. According to AJCC 8th edition, T1b, T2, and T4 patients were at higher risk of death compared with T1a patients (T1b, HR 1.91, P < 0.001; T2, HR 2.29, P < 0.001; T4, HR 4.16, P < 0.001). As in the AJCC 7th edition, AJCC 8th edition T3 patients had a higher HR of death compared with T1 patients (HR 1.65, P  = 0.001) but lower than T1b and T2. AJCC 8th edition. T-category performed slightly better than AJCC 7th edition with a C-index of 0.609 versus 0.590.
  
  
  CONCLUSIONS
  A staging system that perfectly discriminates between stages has not yet been developed, but the AJCC 8th edition was able to better stratify the risk of death of Stage III and T3 patients.
authors.affiliation: Department of Surgery, University of Verona, Verona, Italy.
authors.forename: Gaya
authors.initials: G
authors.lastname: Spolverato
authors.affiliation: Department of Surgery, University of Verona, Verona, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Bagante
authors.affiliation: Department of Surgery, Johns Hopkins Hospital, Baltimore, Maryland.
authors.forename: Matthew
authors.initials: M
authors.lastname: Weiss
authors.affiliation: Department of Surgery, Fundeni Clinical Institute, Bucharest, Romania.
authors.forename: Sorin
authors.initials: S
authors.lastname: Alexandrescu
authors.affiliation: Department of Surgery, Curry Cabral Hospital, Lisbon, Portugal.
authors.forename: Hugo P
authors.initials: HP
authors.lastname: Marques
authors.affiliation: Department of Surgery, Ospedale San Raffaele, Milan, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Aldrighetti
authors.affiliation: Department of Surgery, Emory University, Atlanta, Georgia.
authors.forename: Shishir K
authors.initials: SK
authors.lastname: Maithel
authors.affiliation: Department of Surgery, Royal Prince Alfred Hospital, University of Sydney, Sydney, Australia.
authors.forename: Carlo
authors.initials: C
authors.lastname: Pulitano
authors.affiliation: Department of Surgery, University of Virginia, Charlottesville, Virginia.
authors.forename: Todd W
authors.initials: TW
authors.lastname: Bauer
authors.affiliation: Department of Surgery, Eastern Hepatobiliary Surgery Hospital, Shanghai, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Shen
authors.affiliation: Department of Surgery, Stanford University, Stanford, California.
authors.forename: George A
authors.initials: GA
authors.lastname: Poultsides
authors.affiliation: Department of Hepatobiliopancreatic Surgery and Liver Transplantation, AP-HP, Beaujon Hospital, Clichy, France.
authors.forename: Oliver
authors.initials: O
authors.lastname: Soubrane
authors.affiliation: Division of General Surgery, Department of Surgery, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Martel
authors.affiliation: Department of Surgery, Erasmus University Medical Centre, Rotterdam, Netherlands.
authors.forename: Bas Groot
authors.initials: BG
authors.lastname: Koerkamp
authors.affiliation: Department of Surgery, University of Verona, Verona, Italy.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Guglielmi
authors.affiliation: Division of Gastroenterological Surgery, Yokohama City University School of Medicine, Yokohama, Japan.
authors.forename: Endo
authors.initials: E
authors.lastname: Itaru
authors.affiliation: Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Pawlik
mesh_terms: D000368:Aged; D001650:Bile Duct Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D018281:Cholangiocarcinoma / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods
keywords: 8th edition; AJCC; ICC; staging; surgery