title: The impact of lymph node number on survival in patients with lymph node-negative pancreatic cancer.
abstract: OBJECTIVE
  The role of lymph node (LN) dissection for pancreatic cancer remains uncertain, and guidelines for a minimum LN number have not been established. We hypothesized that LN number in node-negative (N0) pancreatic cancer influences survival.
  
  
  METHODS
  The Surveillance, Epidemiology, and End Results database was queried for patients undergoing resection for N0 pancreatic adenocarcinoma between 1988 and 2003. Lymph node number was categorized as 1-10, 11-20, and >20.
  
  
  RESULTS
  In a cohort of 1915 patients, the median LN number was 7 (range 1-57); 1365 (71%) patients had <11 LN. Survival was significantly better in the 11 to 20 compared with the 1-10 group (median, 20 vs 15 months, respectively, P < 0.0001); no difference was observed between the 11-20 and >20 groups (median, 20 vs 23 months, respectively, P = 0.14). Multivariate analysis demonstrated the prognostic significance of LN number for determining overall survival (hazard ratio 0.98, 95% confidence interval: 0.97-0.99; P<0.0001).
  
  
  CONCLUSIONS
  Pancreatic cancer lymphadenectomy with examination of >10 LN is associated with improved survival in N0 disease and should be considered a benchmark for adequacy of surgery and/or pathology. Currently, only a minority of patients are assessed by this measure. The variation in LN number may be indicative of diverse surgical technique and/or pathologic analysis and warrants further investigation.
authors.affiliation: Department of General Oncologic Surgery, City of Hope National Medical Center, Duarte, CA 91010, USA.
authors.forename: Minia
authors.initials: M
authors.lastname: Hellan
authors.forename: Can-Lan
authors.initials: CL
authors.lastname: Sun
authors.forename: Avo
authors.initials: A
authors.lastname: Artinyan
authors.forename: Pablo
authors.initials: P
authors.lastname: Mojica-Manosa
authors.forename: Smita
authors.initials: S
authors.lastname: Bhatia
authors.forename: Joshua D I
authors.initials: JD
authors.lastname: Ellenhorn
authors.forename: Joseph
authors.initials: J
authors.lastname: Kim
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008197:Lymph Node Excision / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010180:Pancreatectomy / Q000706:statistics & numerical data; D010190:Pancreatic Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D016577:Pancreaticoduodenectomy / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D012042:Registries; D018570:Risk Assessment; D018426:SEER Program; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology