title: The effect of hepatic steatosis on survival following resection of colorectal liver metastases in patients without preoperative chemotherapy.
abstract: BACKGROUND
  Hepatic steatosis, a common condition associated with insulin resistance and excess body weight, is reported to be associated with an increased risk for perioperative mortality in patients undergoing resection of colorectal liver metastases (CLM), but its impact upon longterm survival is less well documented.
  
  
  METHODS
  The effects of background liver pathology, categorized as 'normal', 'with steatosis' and 'other', on perioperative mortality, overall survival (OS) and cancer-specific survival (CSS) were assessed in patients undergoing resection for CLM according to data maintained in the LiverMetSurvey database. As preoperative chemotherapy may confound the effects of steatosis, patients who had been given preoperative chemotherapy were excluded. Survival analyses included log-rank tests for comparisons, and multivariate Cox models, including well-established prognosticators.
  
  
  RESULTS
  Of 5853 patients who underwent first-time liver resection without preoperative chemotherapy, 1793 (30.6%) had background steatosis. Rates of 90-day perioperative mortality in patients with normal, steatosis and other pathologies were 2.8%, 2.1% and 4.9%, respectively. Steatosis was associated with improved 5-year OS (47.4% versus 43.0%; log rank, P = 0.0017) and CSS (56.1% versus 50.3%; P = 0.002) compared with normal background liver. After adjustments, the survival advantage associated with steatosis remained (hazard ratio = 0.806, 95% confidence interval 0.717-0.905 for CSS).
  
  
  CONCLUSIONS
  The paradoxical survival advantage observed in patients with steatosis undergoing liver resection for CLM generates a hypothesis that peri-diagnosis of excess body adiposity has a survival protective effect that warrants further research.
authors: Institute of Cancer Sciences, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK. ed.parkin@christie.nhs.uk
authors: Ed
authors: E
authors: Parkin
authors: Derek A
authors: DA
authors: O'Reilly
authors: Rene
authors: R
authors: Adam
authors: Gernot M
authors: GM
authors: Kaiser
authors: Christophe
authors: C
authors: Laurent
authors: Dominique
authors: D
authors: Elias
authors: Lorenzo
authors: L
authors: Capussotti
authors: Andrew G
authors: AG
authors: Renehan
mesh_terms: D000368:Aged; D017024:Chemotherapy, Adjuvant; D003082:Colectomy; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005060:Europe; D005234:Fatty Liver / Q000150:complications* / Q000401:mortality / Q000473:pathology; D005260:Female; D006498:Hepatectomy / Q000009:adverse effects / Q000401:mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000401:mortality / Q000556:secondary* / Q000601:surgery; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy; D016017:Odds Ratio; D016016:Proportional Hazards Models; D012042:Registries; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome