title: The neutrophil-to-lymphocyte ratio predicts major perioperative complications in patients undergoing colorectal surgery.
abstract: OBJECTIVE
  The objective of the study was to evaluate the association between the neutrophil-to-lymphocyte ratio (NLR) and the occurrence of perioperative complications in patients undergoing colorectal surgery.
  
  
  METHODS
  A retrospective cohort study was conducted of patients who underwent resection for suspected or confirmed colorectal cancer from 2004 to 2012. Patient cohorts with a high vs low NLR were defined by receiver operating characteristic curve analysis. Univariate and multivariate logistic regression was used to determine whether patients with elevated NLR were more likely to suffer perioperative complications.
  
  
  RESULTS
  In all, 583 patients were included. A preoperative NLR greater than or equal to 2.3 was significantly associated with a major perioperative complication (OR 2.52, 95% CI 1.26-5.01). On multivariate analysis, a high NLR (OR 2.25, 95% CI 1.12-4.52) and Charlson Comorbidity Index ≥ 3 (OR 4.55, 95% CI 2.17-9.56) were significantly related to major morbidity. No relationships were found between an elevated preoperative NLR and complication type, although there was a trend towards the occurrence of anastomotic leakage.
  
  
  CONCLUSIONS
  Preoperative NLR ≥ 2.3 may be a risk factor for major surgical complications following colorectal resection. Further study is needed to validate this threshold and evaluate the clinical implications of these findings.
authors.affiliation: Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: J M
authors.initials: JM
authors.lastname: Josse
authors.affiliation: Division of General Surgery, University Health Network, Toronto, Ontario, Canada.
authors.forename: M C
authors.initials: MC
authors.lastname: Cleghorn
authors.affiliation: Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: K M
authors.initials: KM
authors.lastname: Ramji
authors.affiliation: Department of Biostatistics, Princess Margaret Cancer Center, Toronto, Ontario, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Division of General Surgery, University Health Network, Toronto, Ontario, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Elnahas
authors.affiliation: Department of Surgery, University of Toronto, Toronto, Ontario, Canada.|Division of General Surgery, University Health Network, Toronto, Ontario, Canada.
authors.forename: T D
authors.initials: TD
authors.lastname: Jackson
authors.affiliation: Department of Surgery, University of Toronto, Toronto, Ontario, Canada.|Division of General Surgery, University Health Network, Toronto, Ontario, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Okrainec
authors.affiliation: Department of Surgery, University of Toronto, Toronto, Ontario, Canada.|Division of General Surgery, University Health Network, Toronto, Ontario, Canada.
authors.forename: F A
authors.initials: FA
authors.lastname: Quereshy
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003106:Colon / Q000601:surgery; D013505:Digestive System Surgical Procedures / Q000009:adverse effects* / Q000379:methods; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000166:cytology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009504:Neutrophils; D011183:Postoperative Complications / Q000209:etiology*; D011237:Predictive Value of Tests; D057234:Preoperative Period; D012372:ROC Curve; D012007:Rectum / Q000601:surgery; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
keywords: Colorectal surgery; neutrophil-to-lymphocyte ratio; perioperative complications