title: The More the Better-Lower Rate of Stage Migration and Better Survival in Patients With Retrieval of 20 or More Regional Lymph Nodes in Pancreatic Cancer: A Population-Based Propensity Score Matched and Trend SEER Analysis.
abstract: The aim of this study was to assess the influence of regional lymph node (RLN) retrieval on stage migration and survival in pancreatic cancer.
  
  
  
  A total of 7685 stage I and II pancreatic cancer patients were identified in the Surveillance, Epidemiology, and End Results database in 2004-2011. The impact of RLN was assessed using Cox regression, propensity score methods, and joinpoint regression.
  
  
  
  In 3079 patients, 1 to 10 RLNs were retrieved; in 2799 patients, 11 to 19 RLNs, and in 1807 patients, 20+ RLNs. The rate of node-positive pancreatic cancer increased with the number of retrieved RLN. This trend continued beyond 10 retrieved RLN (P < 0.001). In unadjusted analysis, retrieval of RLN did not influence survival (P = 0.178). When adjusting for significant bias in staging variables (P < 0.001), retrieval of 20+ RLNs compared to 11 to 19 RLNs was associated with an increased survival in node-negative (hazard ratio, 0.78; 95% confidence interval, 0.62-0.98; P = 0.033) and node-positive cancer (hazard ratio, 0.83; 95% confidence interval, 0.74-0.93; P = 0.002).
  
  
  
  This population-based propensity score-adjusted investigation demonstrated that more retrieved RLNs in pancreatic cancer decreases the rate of stage migration and improves the oncological outcome in node-negative and positive cancer. Contradictory results may be explained by a bias in the cancer characteristics for a different extent of RLN retrieval.
authors.affiliation: From the *Department of General, Visceral, Endocrine and Transplantation Surgery, Kantonsspital St. Gallen, St. Gallen, Switzerland; †Institute of Medical Biometry and Informatics, University of Heidelberg, Heidelberg; and ‡Department of Surgery, Universitätsmedizin Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
authors.forename: Rene
authors.initials: R
authors.lastname: Warschkow
authors.forename: Bernhard
authors.initials: B
authors.lastname: Widmann
authors.forename: Ulrich
authors.initials: U
authors.lastname: Beutner
authors.forename: Lukas
authors.initials: L
authors.lastname: Marti
authors.forename: Thomas
authors.initials: T
authors.lastname: Steffen
authors.forename: Marc
authors.initials: M
authors.lastname: Schiesser
authors.forename: Bruno M
authors.initials: BM
authors.lastname: Schmied
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000473:pathology*; D011379:Prognosis; D057216:Propensity Score; D016016:Proportional Hazards Models; D018426:SEER Program / Q000706:statistics & numerical data*; D014481:United States