title: The association of adjuvant therapy with survival at the population level following pancreatic adenocarcinoma resection.
abstract: BACKGROUND
  Using a retrospective observational cohort approach, the overall survival (OS) following curative-intent resection of pancreatic adenocarcinoma (PC) was defined at the population level according to adjuvant treatment, and predictors of OS were identified.
  
  
  METHODS
  Patients undergoing resection of PC in the province of Ontario between 2005 and 2010 were identified using the provincial cancer registry, and linked to databases that include all treatments received and outcomes experienced in the province. Pathology reports were abstracted for staging and margin status. Patients were identified as having received chemotherapy (CT), chemoradiation therapy (CRT), or no adjuvant treatment (NAT). Kaplan-Meier survival analysis of patients surviving ≥ 6 months was performed, and predictors of OS identified by log-rank test. Cox multivariable analysis was used to define independent predictors of OS.
  
  
  RESULTS
  Among the 473 patients undergoing PC resection, the median survival was 17.8 months; for the 397 who survived ≥ 6 months following surgery, the 5-year OS for the CT, CRT, and NAT groups was 21%, 16%, and 17%, respectively (p = 0.584). Lymph node-negative patients demonstrated improved OS associated with chemotherapy on multivariable analysis (HR = 2.20, 95% CI = 1.25-3.83 for NAT vs. CT).
  
  
  CONCLUSIONS
  Following PC resection, only patients with negative lymph nodes demonstrated improved OS associated with adjuvant chemotherapy.
authors.affiliation: Division of General Surgery, Department of Surgery, University of Toronto, Toronto, ON, Canada.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Kagedan
authors.affiliation: Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
authors.forename: Ravish S
authors.initials: RS
authors.lastname: Raju
authors.affiliation: Department of Surgery, Maimonides Medical Center, Brooklyn, NY, USA.
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Dixon
authors.affiliation: Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Shin
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, ON, Canada.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, ON, Canada.
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.affiliation: Division of General Surgery, Department of Surgery, University of Toronto, Toronto, ON, Canada.
authors.forename: Maryam
authors.initials: M
authors.lastname: Elmi
authors.affiliation: Department of Surgery, Saint Barnabas Medical Center, Livingston, NJ, USA.
authors.forename: Abraham
authors.initials: A
authors.lastname: El-Sedfy
authors.affiliation: Sunnybrook Health Sciences Centre, Toronto, ON, Canada; Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Institute for Clinical Evaluative Sciences, Toronto, ON, Canada.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Paszat
authors.affiliation: Sunnybrook Health Sciences Centre, Toronto, ON, Canada; Institute for Clinical Evaluative Sciences, Toronto, ON, Canada; Institute of Health Policy, Management & Evaluation, University of Toronto, Toronto, ON, Canada.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kiss
authors.affiliation: Sunnybrook Health Sciences Centre, Toronto, ON, Canada; Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Institute for Clinical Evaluative Sciences, Toronto, ON, Canada.
authors.forename: Craig C
authors.initials: CC
authors.lastname: Earle
authors.affiliation: Health Outcomes and PharmacoEconomic (HOPE) Research Centre, Sunnybrook Research Institute, Toronto, ON, Canada.
authors.forename: Nicole
authors.initials: N
authors.lastname: Mittmann
authors.affiliation: Division of General Surgery, Department of Surgery, University of Toronto, Toronto, ON, Canada; Sunnybrook Health Sciences Centre, Toronto, ON, Canada; Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Institute for Clinical Evaluative Sciences, Toronto, ON, Canada; Institute of Health Policy, Management & Evaluation, University of Toronto, Toronto, ON, Canada. Electronic address: natalie.coburn@sunnybrook.ca.
authors.forename: Natalie G
authors.initials: NG
authors.lastname: Coburn
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000401:mortality / Q000556:secondary / Q000628:therapy*; D059186:Chemoradiotherapy, Adjuvant; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D009864:Ontario; D010180:Pancreatectomy / Q000009:adverse effects / Q000401:mortality; D010190:Pancreatic Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D016016:Proportional Hazards Models; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome