title: Impact of anastomotic leak on recurrence and survival after colorectal cancer surgery: a BioGrid Australia analysis.
abstract: BACKGROUND
  There is conflicting evidence regarding the oncological impact of anastomotic leak following colorectal cancer surgery. This study aims to test the hypothesis that anastomotic leak is independently associated with local recurrence and overall and cancer-specific survival.
  
  
  METHODS
  Analysis of prospectively collected data from multiple centres in Victoria between 1988 and 2015 including all patients who underwent colon or rectal resection for cancer with anastomosis was presented. Overall and cancer-specific survival rates and rates of local recurrence were compared using Cox regression analysis.
  
  
  RESULTS
  A total of 4892 patients were included, of which 2856 had completed 5-year follow-up. The overall anastomotic leak rate was 4.0%. Cox regression analysis accounting for differences in age, sex, body mass index, American Society of Anesthesiologists score and tumour stage demonstrated that anastomotic leak was associated with significantly worse 5-year overall survival (χ2= 6.459, P = 0.011) for colon cancer, but only if early deaths were included. There was no difference in 5-year colon cancer-specific survival (χ2= 0.582, P = 0.446) or local recurrence (χ2= 0.735, P = 0.391). For rectal cancer, there was no difference in 5-year overall survival (χ2= 0.266, P = 0.606), cancer-specific survival (χ2= 0.008, P = 0.928) or local recurrence (χ2= 2.192, P = 0.139).
  
  
  CONCLUSIONS
  Anastomotic leak may reduce 5-year overall survival in colon cancer patients but does not appear to influence the 5-year overall survival in rectal cancer patients. There was no effect on local recurrence or cancer-specific survival.
authors.affiliation: Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Tarik
authors.identifier: http://orcid.org/0000-0002-4918-8871
authors.initials: T
authors.lastname: Sammour
authors.affiliation: Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia.|Colorectal Unit, The Royal Melbourne Hospital, Melbourne, Victoria, Australia.
authors.forename: Ian P
authors.initials: IP
authors.lastname: Hayes
authors.affiliation: Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia.|Colorectal Unit, The Royal Melbourne Hospital, Melbourne, Victoria, Australia.
authors.forename: Ian T
authors.initials: IT
authors.lastname: Jones
authors.affiliation: Colorectal Unit, Department of Surgery, Box Hill Hospital, Melbourne, Victoria, Australia.
authors.forename: Malcolm C
authors.initials: MC
authors.lastname: Steel
authors.affiliation: Colorectal Unit, Department of Surgery, Western Hospital, Melbourne, Victoria, Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: Faragher
authors.affiliation: Department of Medical Oncology, Walter + Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Gibbs
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D057868:Anastomotic Leak / Q000453:epidemiology*; D001315:Australia; D003110:Colonic Neoplasms / Q000401:mortality* / Q000601:surgery*; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000401:mortality* / Q000601:surgery*; D015996:Survival Rate; D055815:Young Adult
keywords: anastomosis; anastomotic leak; leak; recurrence; survival