title: Anastomotic leakage is associated with impaired overall and disease-free survival after curative rectal cancer resection: a propensity score analysis.
abstract: BACKGROUND
  Whether anastomotic leakage (AL) has a negative impact on survival remains a matter of debate. This study aimed to assess the impact of AL on the overall and disease-free survival of patients undergoing curative resection of stages 1-3 rectal cancer using propensity-scoring methods.
  
  
  METHODS
  In a single-center study, 570 patients undergoing curative resection of stages 1-3 rectal cancer between January 2002 and December 2011 were assessed. The mean follow-up period was 4.7 ± 2.9 years. Patients who did and did not experience AL were compared using Cox regression and propensity score analyses.
  
  
  RESULTS
  Overall, 51 patients (8.9 %) experienced an AL. The characteristics of the patients were highly biased concerning AL (propensity score, 0.16 ± 0.12 vs. 0.09 ± 0.07; P < 0.001). Anastomotic leakage was uniformly associated with a significantly increased risk of mortality in unadjusted analysis [hazard ratio (HR) 2.30; 95 % confidence interval (CI) 1.40-3.76; P = 0.003], multivariable Cox regression (HR 2.27; 95 % CI 1.33-3.88; P = 0.005), and propensity score-adjusted Cox regression (HR 2.07; 95 % CI 1.21-3.55; P = 0.014). Similarly, disease-free survival was significantly impaired in patients who experienced AL according to unadjusted analysis (HR 1.88; 95 % CI 1.19-2.95; P = 0.011), multivariable Cox regression (HR 1.90; 95 % CI 1.17-3.09; P = 0.014), and propensity score-adjusted Cox regression (HR 2.31; 95 % CI 1.40-3.80; P = 0.002).
  
  
  CONCLUSIONS
  This is the first propensity score-based analysis providing evidence that oncologic outcome may be impaired after curative rectal cancer resection in patients with AL.
authors.affiliation: Department of General, Visceral, and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: Yakup
authors.initials: Y
authors.lastname: Kulu
authors.forename: Ignazio
authors.initials: I
authors.lastname: Tarantio
authors.forename: Rene
authors.initials: R
authors.lastname: Warschkow
authors.forename: Sandra
authors.initials: S
authors.lastname: Kny
authors.forename: Martin
authors.initials: M
authors.lastname: Schneider
authors.forename: Bruno M
authors.initials: BM
authors.lastname: Schmied
authors.forename: Markus W
authors.initials: MW
authors.lastname: Büchler
authors.forename: Alexis
authors.initials: A
authors.lastname: Ulrich
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D000368:Aged; D000714:Anastomosis, Surgical / Q000009:adverse effects*; D057868:Anastomotic Leak / Q000209:etiology / Q000401:mortality*; D013505:Digestive System Surgical Procedures / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D009367:Neoplasm Staging; D011379:Prognosis; D057216:Propensity Score; D012004:Rectal Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies; D015996:Survival Rate