title: Survival analysis and prognostic nomogram for patients undergoing resection of extrahepatic cholangiocarcinoma.
abstract: BACKGROUND
  Tumor location of extrahepatic cholangiocarcinoma (CCA) might influence survival after resection.
  
  
  METHODS
  A consecutive series of 175 patients who had undergone a potentially curative resection of extrahepatic CCA was analyzed. We calculated concordance indices of different constructed prognostic models for survival including TNM (tumour-node-metastasis) staging and developed a nomogram of the most sensitive model.
  
  
  RESULTS
  Overall cancer-specific survival rates were 83%, 58%, and 26% at 1, 2, and 5 years, respectively. Cancer-specific survival according to location was 42% for proximal, 23% for mid, and 19% for distal CCA after 5 years. Tumor location was not an independent significant predictor (P = 0.06). A prognostic model using all potential prognostic variables predicted survival better compared with TNM staging (concordance index 0.65 versus 0.63). A reduced model containing only lymph node status, microscopically residual tumor status, and tumor differentiation grade, also outperformed TNM staging (concordance index 0.66).
  
  
  CONCLUSIONS
  Tumor location of extrahepatic CCA does not independently predict cancer-specific survival after resection. We developed a nomogram, based on a prognostic model with lymph node status, microscopically residual tumor status of resection margins, and tumor differentiation grade, that predicted survival better than TNM staging.
authors.affiliation: Departments of Surgery, Amsterdam, The Netherlands.
authors.forename: N A
authors.initials: NA
authors.lastname: van der Gaag
authors.affiliation: Departments of Surgery, Amsterdam, The Netherlands.
authors.forename: J J
authors.initials: JJ
authors.lastname: Kloek
authors.affiliation: Departments of Surgery, Amsterdam, The Netherlands.
authors.forename: J K
authors.initials: JK
authors.lastname: de Bakker
authors.affiliation: Departments of Surgery, Amsterdam, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Musters
authors.affiliation: Departments of Clinical Epidemiology, Biostatistics and Bioinformatics, Amsterdam, The Netherlands.
authors.forename: R B
authors.initials: RB
authors.lastname: Geskus
authors.affiliation: Departments of Surgery, Amsterdam, The Netherlands.
authors.forename: O R C
authors.initials: ORC
authors.lastname: Busch
authors.affiliation: Departments of Pathology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Bosma
authors.affiliation: Departments of Surgery, Amsterdam, The Netherlands.
authors.forename: D J
authors.initials: DJ
authors.lastname: Gouma
authors.affiliation: Departments of Surgery, Amsterdam, The Netherlands. Electronic address: t.m.vangulik@amc.uva.nl.
authors.forename: T M
authors.initials: TM
authors.lastname: van Gulik
mesh_terms: D000368:Aged; D001650:Bile Duct Neoplasms / Q000601:surgery*; D001653:Bile Ducts, Intrahepatic / Q000601:surgery*; D018281:Cholangiocarcinoma / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016019:Survival Analysis