title: Prognostic impact of lymph node metastasis in distal cholangiocarcinoma.
abstract: BACKGROUND
  The aim of the study was to investigate the prognostic impact of lymph node metastasis in cholangiocarcinoma using three different classifications.
  
  
  METHODS
  Patients who underwent pancreaticoduodenectomy for distal cholangiocarcinoma in 24 hospitals in Japan between 2001 and 2010 were included. Survival was calculated by means of the Kaplan-Meier method and differences between subgroups were assessed with the log rank test. The Cox proportional hazards model was used to identify independent predictors of survival. χ(2) scores were calculated to determine the cut-off value of the number of involved nodes, lymph node ratio (LNR) and total lymph node count (TLNC) for discriminating survival.
  
  
  RESULTS
  Some 370 patients were included. The median (range) TLNC was 19 (3-59). Nodal metastasis occurred in 157 patients (42·4 per cent); the median (range) number of involved nodes and LNR were 2 (1-19) and 0·11 (0·02-0·80) respectively. Four or more involved nodes was associated with a significantly shorter median survival (1·3 versus 2·2 years; P = 0·001), as was a LNR of at least 0·17 (1·4 versus 2·3 years; P = 0·002). Involvement of nodes along the common hepatic artery, present in 21 patients (13·4 per cent), was also associated with a shorter survival (median 1·3 versus 2·1 years; P = 0·046). Multivariable analysis among 157 node-positive patients identified the number of involved nodes as an independent prognostic factor (risk ratio 1·87; P = 0·002).
  
  
  CONCLUSIONS
  The number of involved nodes was a strong predictor of survival in patients with distal cholangiocarcinoma.
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kiriyama
authors.forename: T
authors.initials: T
authors.lastname: Ebata
authors.forename: T
authors.initials: T
authors.lastname: Aoba
authors.forename: Y
authors.initials: Y
authors.lastname: Kaneoka
authors.forename: T
authors.initials: T
authors.lastname: Arai
authors.forename: Y
authors.initials: Y
authors.lastname: Shimizu
authors.forename: M
authors.initials: M
authors.lastname: Nagino
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D001653:Bile Ducts, Intrahepatic / Q000601:surgery; D018281:Cholangiocarcinoma / Q000401:mortality* / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D005260:Female; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D008197:Lymph Node Excision / Q000401:mortality; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D059351:Organ Sparing Treatments / Q000379:methods / Q000401:mortality; D016577:Pancreaticoduodenectomy / Q000379:methods / Q000401:mortality*; D011379:Prognosis; D011446:Prospective Studies