title: Lymph node ratio predicts recurrence and survival after R0 resection for non-small cell lung cancer.
abstract: BACKGROUND
  Current TNM non-small cell lung cancer (NSCLC) staging uses only the anatomic location of lymph nodes to define N status. Several other cancer staging systems have found lymph node ratio (LNR)-the number of positive lymph nodes/total lymph nodes resected-to be a better predictor of survival after resection. The purpose of this study is to evaluate LNR as a predictor of recurrence and survival after R0 resection for NSCLC.
  
  
  METHODS
  A total of 1,143 consecutive patients underwent R0 resection for NSCLC between 1999 and 2008 at a high-volume single institution with 26% (n = 302) having N1 and N2 disease. The primary endpoints of the study were long-term survival and recurrence as a function of LNR. Cox proportional hazard models and Kaplan-Meier survival analyses were utilized to assess associations between LNR, N status, and pathologic stage with survival and recurrence after lung cancer resection.
  
  
  RESULTS
  Median follow-up was 44 months and was complete in 97% of patients. Nodal status of patients in this study was as follows: N0 disease, 73.5%; N1 disease, 18.7%; and N2 disease, 7.8%. There were 132 recurrences in patients with nodal disease (43.7%). The pathologic stage of patients in the study was as follows: stage IIA, 47%; stage IIB, 17%; stage IIIA, 35%; and stage IIIB, 1%. Mean total number of lymph nodes sampled was 11.1 ± 6.0 and mean number of positive lymph nodes 2.4 ± 2.0. Upon statistical modeling, LNR was found to be independently associated with decreased survival after resection for NSCLC (hazard ratio 2.63, confidence interval: 1.41 to 4.91, p = 0.002).
  
  
  CONCLUSIONS
  In patients undergoing resection for NSCLC, increasing lymph node ratio is independently associated with decreased survival and decreased time to recurrence after R0 resection.
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Department of Surgery, University of Virginia, Charlottesville, Virginia.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Taylor
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Department of Surgery, University of Virginia, Charlottesville, Virginia.
authors.forename: Damien J
authors.initials: DJ
authors.lastname: LaPar
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Department of Surgery, University of Virginia, Charlottesville, Virginia.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Thomas
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Department of Surgery, University of Virginia, Charlottesville, Virginia.
authors.forename: Matthew
authors.initials: M
authors.lastname: Persinger
authors.affiliation: Department of Pathology, University of Virginia, Charlottesville, Virginia.
authors.forename: Edward B
authors.initials: EB
authors.lastname: Stelow
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Department of Surgery, University of Virginia, Charlottesville, Virginia.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Kozower
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Department of Surgery, University of Virginia, Charlottesville, Virginia.
authors.forename: Christine L
authors.initials: CL
authors.lastname: Lau
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Department of Surgery, University of Virginia, Charlottesville, Virginia. Electronic address: djones@virginia.edu.
authors.forename: David R
authors.initials: DR
authors.lastname: Jones
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D009367:Neoplasm Staging; D011013:Pneumonectomy; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D013997:Time Factors
keywords: 10