title: Prognosis impact of the lymph node ratio in patients with colon adenocarcinoma: a single-centre experience.
abstract: OBJECTIVE
  Recently, the positive lymph node ratio (LNR) is considered a new prognostic parameter on survival and time to progression for patients with colon cancer. The aim of this study was to determine the prognostic impact of the LNR as an independent factor for overall survival (OS) and disease-free survival (DFS) in patients with colon cancer regardless of their clinical stage.
  
  
  METHODS
  We retrospectively identified 85 consecutive patients diagnosed with colon adenocarcinoma treated in our centre during 2010. We categorized patients according to a LNR cutoff of 0.25. Three-year OS and DFS were determined according to the Kaplan-Meier method. A Cox proportional model was used to assess the influence of other prognostic variables on each outcome.
  
  
  RESULTS
  After median follow-up of 34.8 months, neither median OS nor DFS has been reached by any of the subgroups. Nevertheless, patients with a LNR ≥ 0.25 exhibited a higher risk of death (hazard ratio, 3.10; 95 % confidence interval (CI), 1.38-7.01; log-rank test: p = 0.006) and a shorter interval without progression (hazard ratio, 6.59; 95 % CI, 1.96-22.15; log-rank test: p = 0.002.) than patients with LNR < 0.25. After adjusting for prespecifed variables, the impact of a LNR ≥ 0.25 was independently associated with OS (hazard ratio, 2.8; 95 % CI, 1.01-7.73; p = 0.04) and DFS (hazard ratio, 7.07; 95 % CI, 1.23-40.45; p = 0.03).
  
  
  CONCLUSIONS
  LNR was independently associated with OS and DFS in patients with colon adenocarcinoma regardless of its clinical stage.
authors.affiliation: Department of Pharmacology, University of Costa Rica, San José, Costa Rica, allan.ramos@ucr.ac.cr.
authors.forename: Allan
authors.initials: A
authors.lastname: Ramos-Esquivel
authors.forename: Melissa
authors.initials: M
authors.lastname: Juárez
authors.forename: Ileana
authors.initials: I
authors.lastname: González
authors.forename: Juan
authors.initials: J
authors.lastname: Porras
authors.forename: Luis
authors.initials: L
authors.lastname: Rodriguez
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D002288:Adenocarcinoma, Mucinous / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate