title: Novel methods for clinical risk stratification in patients with colorectal liver metastases.
abstract: OBJECTIVE
  Colorectal cancer patients with liver-confined metastases are classified as stage IV, but their prognoses can differ from metastases at other sites. In this study, we suggest a novel method for risk stratification using clinically effective factors.
  
  
  METHODS
  Data on 566 consecutive patients with colorectal liver metastasis (CLM) between 1989 and 2010 were analyzed. This analysis was based on principal component analysis (PCA).
  
  
  RESULTS
  The survival rate was affected by carcinoembryonic antigen (CEA) level (p < 0.001; risk ratio, 1.90), distribution of liver metastasis (p=0.014; risk ratio, 1.46), and disease-free interval (DFI; p < 0.001; risk ratio, 1.98). When patients were divided into three groups according to PCA score using significantly affected factors, they showed significantly different survival patterns (p < 0.001).
  
  
  CONCLUSIONS
  The PCA scoring system based on CEA level, distribution of liver metastasis, and DFI may be useful for preoperatively determining prognoses in order to assist in clinical decisionmaking and designing future clinical trials for CLM treatment.
authors.affiliation: Oral Cancer Research Institute, Seoul, Korea.
authors.forename: Ki-Yeol
authors.initials: KY
authors.lastname: Kim
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Nam Kyu
authors.initials: NK
authors.lastname: Kim
authors.affiliation: Oral Cancer Research Institute, Seoul, Korea ; Department of Oral and Maxillofacial Surgery, Yonsei University College of Dentistry, Seoul, Korea.
authors.forename: In-Ho
authors.initials: IH
authors.lastname: Cha
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Joong Bae
authors.initials: JB
authors.lastname: Ahn
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jin Sub
authors.initials: JS
authors.lastname: Choi
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Gi-Hong
authors.initials: GH
authors.lastname: Choi
authors.affiliation: Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Joon Suk
authors.initials: JS
authors.lastname: Lim
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kang Young
authors.initials: KY
authors.lastname: Lee
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seung Hyuk
authors.initials: SH
authors.lastname: Baik
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Byung Soh
authors.initials: BS
authors.lastname: Min
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyuk
authors.initials: H
authors.lastname: Hur
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jae Kyung
authors.initials: JK
authors.lastname: Roh
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sang Joon
authors.initials: SJ
authors.lastname: Shin
keywords: Colorectal neoplasms; Liver metastasis; Patient stratification; Risk calculation