title: Simplified staging system for predicting the prognosis of patients with resectable liver metastasis: development and validation.
abstract: OBJECTIVE
  Although several staging systems for colorectal liver metastasis have been proposed, simple and generally accepted staging systems are not available for this disease. We hypothesized that more detailed analysis of primary colorectal cancer may make it possible to develop a simple staging system and that its stratification ability may be demonstrated by validation against data from unrelated patients.
  
  
  METHODS
  Retrospective analysis of prospectively documented data, development of a stage, and validation against an unrelated cohort.
  
  
  METHODS
  Four tertiary referral centers.
  
  
  METHODS
  Twenty-two clinicopathologic factors were examined in 369 consecutive patients who underwent curative resection for liver metastasis from colorectal cancer (original cohort). Using the independent prognostic factors, a simplified staging system was developed and was validated by data from 229 unrelated patients (validation cohort).
  
  
  METHODS
  Kaplan-Meier survival curve analyses between different prognostic groups in the cohorts.
  
  
  RESULTS
  Multivariate analysis revealed several independent prognostic variables, including hepatic lymph node metastasis (relative risk 4.39), 4 or more colorectal lymph node metastases (RR 1.50), carcinoembryonic antigen level of 50 ng/mL or higher (RR 1.29), and multiple hepatic metastases (RR 1.27). Patients with hepatic lymph node metastasis were assigned to stage 4, and the remaining patients were divided according to number of factors: none, stage 1; 1, stage 2; 2 or 3, stage 3. In the original cohort, median survival in stages 1, 2, 3, and 4 was 7.2, 3.5, 2.0, and 1.3 years, respectively. In the validation cohort, these values were 9.6, 4.1, 2.8, and 1.6 years, respectively.
  
  
  CONCLUSIONS
  The proposed simplified staging system was easy to use, was highly predictive of patient outcome, and permitted categorization of patients into treatment groups. Although we validated this staging system, further validation and improvements are needed.
authors: Department of Hepato-Biliary-Pancreatic Surgery, Department of Artificial Organ and Transplantation, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. minagawa-tky@umin.ac.jp
authors: Masami
authors: M
authors: Minagawa
authors: Junji
authors: J
authors: Yamamoto
authors: Tomoo
authors: T
authors: Kosuge
authors: Yutaka
authors: Y
authors: Matsuyama
authors: Shin-Ichi
authors: S
authors: Miyagawa
authors: Masatoshi
authors: M
authors: Makuuchi
mesh_terms: D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006498:Hepatectomy; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008113:Liver Neoplasms / Q000401:mortality / Q000556:secondary* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate