title: Urgent surgery after emergency presentation for colorectal cancer has no impact on overall and disease-free survival: a propensity score analysis.
abstract: BACKGROUND
  It remains a matter of debate whether colorectal cancer resection in an emergency setting negatively impacts on survival. Our objective was therefore to assess the impact of urgent versus elective operation on overall and disease-free survival in patients undergoing resection for colorectal cancer by using propensity score adjusted analysis.
  
  
  METHODS
  In a single-center study patients operated for colorectal cancer between 1989 and 2013 were identified from a prospectively maintained database. Median follow-up was 44 months. Patients with neoadjuvant treatment were excluded. The impact of urgent operation on overall and disease-free survival was assessed using both Cox regression and propensity score analyses.
  
  
  RESULTS
  Of 747 patients with colorectal cancer, 84 (11%) had urgent and 663 elective cancer resection. The propensity score revealed strongly biased patient characteristics (0.22 ± 0.16 vs. 0.10 ± 0.09; P < 0.001). In unadjusted analysis urgent operation was associated with a 35% increased risk of overall mortality (hazard ratio(HR) of death = 1.35, 95% confidence interval(CI):1.02-1.78, P = 0.045). In risk-adjusted Cox regression analysis urgent operation was not associated with poor overall (HR = 1.08, 95%CI:0.79-1.48; P = 0.629) or disease-free survival (HR = 1.02, 95%CI:0.76-1.38; P = 0.877). Similarly in propensity score analysis urgent operation did not influence overall (HR = 0.98, 95% CI:0.74-1.29), P = 0.872) and disease-free survival (HR = 0.89, 95%CI:0.68 to 1.16, P = 0.387).
  
  
  CONCLUSIONS
  This study provides evidence that worse oncologic outcomes after urgent operation for colorectal cancer are caused by clinical circumstances and not due to the urgent operation itself. Urgent operation is not a risk factor for colorectal cancer resection.
authors.affiliation: Department of Surgery, University Hospital Basel, Spitalstrasse 21, 4031, Basel, Switzerland.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Weixler
authors.affiliation: Department of Surgery, Kantonsspital St. Gallen, 9007, St. Gallen, Switzerland.|Institute of Medical Biometry and Informatics, University of Heidelberg, Heidelberg, Germany.
authors.forename: Rene
authors.initials: R
authors.lastname: Warschkow
authors.affiliation: Department of Surgery, University Hospital Basel, Spitalstrasse 21, 4031, Basel, Switzerland.
authors.forename: Michaela
authors.initials: M
authors.lastname: Ramser
authors.affiliation: Department of Surgery, University Hospital Basel, Spitalstrasse 21, 4031, Basel, Switzerland.
authors.forename: Raoul
authors.initials: R
authors.lastname: Droeser
authors.affiliation: Department of Surgery, University Hospital Basel, Spitalstrasse 21, 4031, Basel, Switzerland.|Goshen Center for Cancer Care, Goshen, IN, 46507, USA.
authors.forename: Urs
authors.initials: U
authors.lastname: von Holzen
authors.affiliation: Department of Surgery, University Hospital Basel, Spitalstrasse 21, 4031, Basel, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Oertli
authors.affiliation: Department of Surgery, University Hospital Basel, Spitalstrasse 21, 4031, Basel, Switzerland. christoph.kettelhack@usb.ch.
authors.forename: Christoph
authors.initials: C
authors.lastname: Kettelhack
mesh_terms: D000328:Adult; D000368:Aged; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery*; D013505:Digestive System Surgical Procedures; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011379:Prognosis; D057216:Propensity Score; D016016:Proportional Hazards Models
keywords: Colorectal cancer; Disease-free survival; Emergency surgery; Oncological outcome; Overal survival