title: Palliative surgery in patients with unresectable colorectal liver metastases: a propensity score matching analysis.
abstract: OBJECTIVE
  The current study was primarily intended to determine the best surgical treatment for patients with unresectable liver metastatic colorectal cancer (CRC). In addition, we assessed whether the improvement in survival resulting from palliative resection (PR) of the primary tumor was a function of the extent of liver metastasis.
  
  
  METHODS
  The demographics, tumor characteristics, and survival outcomes of 261 patients who underwent palliative surgery for unresectable liver metastatic CRC were analyzed. A propensity-score model was used to compare the group of patients receiving PR and non-resection (NR).
  
  
  RESULTS
  There were 195 PR patients and 66 NR. The median survival of PR and NR patients was 21 months and 10 months, respectively (P < 0.001). In a Cox multivariate analysis of 51 propensity-score matched pairs, PR resulted in longer survival than NR (Hazard Ratio for NR 1.481; 95% confidence interval: 1.003-2.185; P = 0.048). The extent of liver metastasis only led to better survival of PR than NR patients among patients with limited liver metastasis not among those with extensive liver metastasis (P = 0.001).
  
  
  CONCLUSIONS
  PR appears to result in better survival than NR when the patient's overall condition permits an aggressive approach, especially in patients with limited liver metastases.
authors.affiliation: Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Yong Sik
authors.initials: YS
authors.lastname: Yoon
authors.forename: Chan Wook
authors.initials: CW
authors.lastname: Kim
authors.forename: Seok-Byung
authors.initials: SB
authors.lastname: Lim
authors.forename: Chang Sik
authors.initials: CS
authors.lastname: Yu
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Kim
authors.forename: Tae Won
authors.initials: TW
authors.lastname: Kim
authors.forename: Min-Ju
authors.initials: MJ
authors.lastname: Kim
authors.forename: Jin Cheon
authors.initials: JC
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology*; D005260:Female; D006498:Hepatectomy / Q000379:methods; D006801:Humans; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010166:Palliative Care / Q000379:methods*; D057216:Propensity Score; D056910:Republic of Korea / Q000453:epidemiology; D016896:Treatment Outcome
keywords: Colorectal adenocarcinomas; propensity score matching; surgical treatment; survival