title: Improved long-term outcomes after resection of pancreatic adenocarcinoma: a comparison between two time periods.
abstract: BACKGROUND
  Despite reduced perioperative mortality and routine use of adjuvant therapy following pancreatectomy for pancreatic ductal adenocarcinoma (PDAC), improvement in long-term outcome has been difficult to ascertain. This study compares outcomes in patients undergoing resection for PDAC within a single, high-volume academic institution over two sequential time periods.
  
  
  METHODS
  Retrospective review of patients with resected PDAC, in two cohorts: period 1 (P1), 1991-2000; and period 2 (P2), 2001-2010. Univariate and multivariate analyses using the Cox proportional hazards model were performed to determine prognostic factors associated with long-term survival. Survival was evaluated using Kaplan-Meier analyses.
  
  
  RESULTS
  A total of 179 pancreatectomies were performed during P1 and 310 during P2. Perioperative mortality was 6.7 % (12/179) in P1 and 1.6 % (5/310) in P2 (p = 0.003). P2 had a greater number of lymph nodes resected (17 [0-50] vs. 7 [0-31]; p < 0.001), and a higher lymph node positivity rate (69 % [215/310] vs. 58 % [104/179]; p = 0.021) compared with P1. The adjuvant therapy rate was 30 % (53/179) in P1 and 63 % (195/310) in P2 (p < 0.001). By multivariate analysis, node and margin status, tumor grade, adjuvant therapy, and time period of resection were independently associated with overall survival (OS) for both time periods. Median OS was 16 months (95 % confidence interval [CI] 14-20) in P1 and 27 months (95 % CI 24-30) in P2 (p < 0.001).
  
  
  CONCLUSIONS
  Factors associated with improved long-term survival remain comparable over time. Short- and long-term survival for patients with resected PDAC has improved over time due to decreased perioperative mortality and increased use of adjuvant therapy, although the proportion of 5-year survivors remains small.
authors.affiliation: Department of Surgery, McMaster University, Hamilton, ON, Canada.
authors.forename: Pablo E
authors.initials: PE
authors.lastname: Serrano
authors.forename: Sean P
authors.initials: SP
authors.lastname: Cleary
authors.forename: Neesha
authors.initials: N
authors.lastname: Dhani
authors.forename: Peter T W
authors.initials: PT
authors.lastname: Kim
authors.forename: Paul D
authors.initials: PD
authors.lastname: Greig
authors.forename: Kenneth
authors.initials: K
authors.lastname: Leung
authors.forename: Carol-Anne
authors.initials: CA
authors.lastname: Moulton
authors.forename: Steven
authors.initials: S
authors.lastname: Gallinger
authors.forename: Alice C
authors.initials: AC
authors.lastname: Wei
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010180:Pancreatectomy / Q000401:mortality*; D010190:Pancreatic Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D013997:Time Factors; D055815:Young Adult