title: Extent of lymph node retrieval and pancreatic cancer survival: information from a large US population database.
abstract: BACKGROUND
  Operative therapy of pancreatic cancer is associated with poor survival because of high recurrence rates after pancreatectomy. The effect of lymph node (LN) dissection on survival continues to be debated.
  
  
  METHODS
  A pancreatic cancer data set was created through structured queries to the Surveillance, Epidemiology, and End Results 1973 to 2000 database. Stage information was created according to 6th edition American Joint Committee on Cancer tumor-node-metastasis criteria, and the effect of LN number on survival was analyzed.
  
  
  RESULTS
  Out of a cohort of 20,631 patients with carcinomas of the exocrine pancreas, surgical details were available for 2,787 patients. Procedures included pancreatoduodenectomies (n = 1848; 66%), radical regional pancreatectomies (n = 516; 19%), other partial resections (n = 316; 11%), and total pancreatectomies (n = 107; 4%). For 1666 of these patients with complete clinicopathologic information, the median age was 66 years (range, 22-96 years), with an equal sex ratio. The median number of total LNs examined was 7 (range, 1-52), of positive LNs was 1 (range, 0-34), and of negative LNs was 6 (range, 0-30). Multivariate survival analysis yielded these prognostic variables: number of LNs examined, number of positive LNs, tumor size, extrapancreatic extension, radiotherapy (all P < .0001), and age (P = .0009). The greatest survival differences were observed for negative LN counts of 10 to 15.
  
  
  CONCLUSIONS
  Stage-based survival prediction of pancreatic cancer is strongly influenced by total LN counts and numbers of negative LNs obtained. Although the mechanism remains unclear and could reflect confounding factors (margin status and institutional volume), an attempt to resect and examine at least 15 LNs to yield preferably between 10 and 15 negative LNs seems sensible for curative-intent pancreatectomy.
authors.affiliation: Division of Surgical Oncology, The Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, New Jersey 08903, USA. r.schwarz@umdnj.edu
authors.forename: Roderich E
authors.initials: RE
authors.lastname: Schwarz
authors.forename: David D
authors.initials: DD
authors.lastname: Smith
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000453:epidemiology / Q000401:mortality* / Q000601:surgery; D011379:Prognosis; D018426:SEER Program / Q000706:statistics & numerical data; D015996:Survival Rate; D014481:United States