title: A new staging system for mass-forming intrahepatic cholangiocarcinoma: analysis of preoperative and postoperative variables.
abstract: BACKGROUND
  The objective of this study was to analyze the clinicopathologic variables and the postoperative outcome in patients with mass-forming intrahepatic cholangiocarcinoma (ICC) to identify important factors for predicting postresection prognosis. Although it has been reported that mass-forming ICC has a different etiology and biologic features compared with hepatocellular carcinoma (HCC), patients with ICC have been dealt with clinicopathologically in the same manner as patients with HCC.
  
  
  METHODS
  Sixty patients who underwent hepatectomy for mass-forming ICC with curative intent between 1981 and 1999 were studied. Fourteen preoperative clinical and diagnostic parameters and 12 postoperative surgicopathologic parameters were analyzed.
  
  
  RESULTS
  The rate of operative mortality in this patient cohort was 5%, and the overall 1-year, 3-year, and 5-year survival rates were 68%, 35%, and 29%, respectively, with a median survival of 19.6 months. A multivariate analysis revealed that independent negative prognostic factors were 1) hepatic regional lymph node metastasis, 2) multiple tumor presentation, 3) symptomatic tumor, and 4) the presence of vascular invasion. Using these factors, a new staging system was devised: Stage I disease was defined as a solitary tumor without vascular invasion, Stage II disease was defined as a solitary tumor with vascular invasion, Stage IIIA disease was defined as multiple tumors with or without vascular invasion, Stage IIIB disease was defined as any tumor with regional lymph node metastasis, and Stage IV disease was defined as any tumor with distant metastases. The Kaplan-Meier estimated 3-year survival rate and the median survival for each subgroup were 74% for patients with Stage I disease (median survival is the time when the cumulative survival rate of some patients' group declined to 50%; thus, the median survival could not be calculated in patients with Stage I disease because survival was 74% at the latest follow-up), 48% and 26.2 months for patients with Stage II disease, 18% and 16.8 months for patients with Stage IIIA disease, and 7% and 11.2 months for patients with Stage IIIB disease, respectively (P < 0.0001). None of the patients met the criteria for Stage IV disease.
  
  
  CONCLUSIONS
  The current results support the use of a new staging system for patients with ICC that is simple and predicts well the differences in survival after patients undergo hepatic resection.
authors.affiliation: Department of Surgery, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Okabayashi
authors.forename: J
authors.initials: J
authors.lastname: Yamamoto
authors.forename: T
authors.initials: T
authors.lastname: Kosuge
authors.forename: K
authors.initials: K
authors.lastname: Shimada
authors.forename: S
authors.initials: S
authors.lastname: Yamasaki
authors.forename: T
authors.initials: T
authors.lastname: Takayama
authors.forename: M
authors.initials: M
authors.lastname: Makuuchi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018281:Cholangiocarcinoma / Q000098:blood supply / Q000473:pathology* / Q000601:surgery; D005260:Female; D006498:Hepatectomy; D006801:Humans; D008113:Liver Neoplasms / Q000098:blood supply / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D016609:Neoplasms, Second Primary / Q000473:pathology*; D009389:Neovascularization, Pathologic; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis