title: Lymph node ratio as parameter of regional lymph node involvement in pancreatic cancer.
abstract: OBJECTIVE
  To determine which indicators, anatomical nodal metastasis (Japan Pancreas Society, JPS), number of positive lymph nodes (PLN), or lymph node ratio (LNR), is the best means of assessing lymph node involvement in pancreatic cancer.
  
  
  METHODS
  This retrospective study analyzed 275 patients with pancreatic cancer treated at a single institution. Survival curves according to the JPS, PLN, or LNR were assessed by the Kaplan-Meier method. Prognostic value of each classification was explored by Cox regression analysis after adjustments for clinical factors.
  
  
  RESULTS
  Multivariate analysis showed that, relative to n0 in the JPS, hazard ratios (HR) in n1, n2, and n3 were 1.72, 1.73, and 2.75, respectively, with no difference in survival between n1 and n2. Relative to PLN of 0, the HR in the PLN categories of 1∼2, 3, and >3 were 1.39, 1.65, and 3.03, respectively. Relative to LNR of 0, the HR in the categories of 0 < LNR ≤ 0.1, 0.1 < LNR ≤ 0.2, and LNR > 0.2 were 1.27, 2.00, and 5.58, respectively. An incremental increase in the HR was observed as the LNR category progressed, and differences between the survivals were distinct when stratified by the LNR.
  
  
  CONCLUSIONS
  The LNR was an accurate predictor of survival among three assessment strategies and could be proposed as a candidate for use as N categories, pending validation studies.
authors.affiliation: Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan. suguru@med.nagoya-u.ac.jp.
authors.forename: Suguru
authors.initials: S
authors.lastname: Yamada
authors.affiliation: Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Biostatistics Section, Center for Advanced Medicine and Clinical Research, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hirakawa
authors.affiliation: Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan.
authors.forename: Mitsuro
authors.initials: M
authors.lastname: Kanda
authors.affiliation: Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sugimoto
authors.affiliation: Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kodera
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; 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 / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D012189:Retrospective Studies; D015996:Survival Rate
keywords: Lymph node metastasis; Lymph node ratio; Pancreatic cancer; Prognosis