title: Lymph node ratio as a prognostic factor in patients with pathological N2 non-small cell lung cancer.
abstract: BACKGROUND
  The aim of this study was to investigate whether the lymph node ratio (LNR) was associated with the prognosis of patients, who underwent surgery for pathological N2 non-small cell lung cancer (NSCLC).
  
  
  METHODS
  A total of 182 patients were diagnosed with pathological N2 disease and underwent complete resection surgeries with systematic lymphadenectomies. We counted the number of positives and removed lymph nodes to calculate a ratio between them (LNR). We also investigated the association between skip mediastinal lymph node metastasis and survival.
  
  
  RESULTS
  Univariate analysis of survival in patients with N2 NSCLC showed that the T factor, clinical N factor, and LNR were significant prognostic factors. Multivariate analyses showed that the clinical N stage and LNR were significant independent prognostic factors for patients with pathological N2 NSCLC. Patients with a clinical lymph node status of 0 (cN0) and LNR ≤0.22 showed a significantly higher survival rate than patients with a cN1-2 and LNR ≥0.22 and 5-year survival rates were 47.1 and 10.3%, respectively (p < 0.0001).
  
  
  CONCLUSIONS
  LNR is an important prognostic factor for poor outcome following surgery in patients with N2 disease. The combination of the LNR and cN status provides a valuable prognostic tool.
authors.affiliation: Department of Thoracic, Cardiovascular and General Surgery, Kanazawa University School of Medicine, Takara-machi 13-1, Kanazawa, 920-8640, Japan. masatamu2007@yahoo.co.jp.
authors.forename: Masaya
authors.initials: M
authors.lastname: Tamura
authors.affiliation: Department of Thoracic, Cardiovascular and General Surgery, Kanazawa University School of Medicine, Takara-machi 13-1, Kanazawa, 920-8640, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Matsumoto
authors.affiliation: Department of Thoracic, Cardiovascular and General Surgery, Kanazawa University School of Medicine, Takara-machi 13-1, Kanazawa, 920-8640, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Saito
authors.affiliation: Department of Thoracic, Cardiovascular and General Surgery, Kanazawa University School of Medicine, Takara-machi 13-1, Kanazawa, 920-8640, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Yoshida
authors.affiliation: Department of Thoracic, Cardiovascular and General Surgery, Kanazawa University School of Medicine, Takara-machi 13-1, Kanazawa, 920-8640, Japan.
authors.forename: Munehisa
authors.initials: M
authors.lastname: Takata
authors.affiliation: Department of Thoracic, Cardiovascular and General Surgery, Kanazawa University School of Medicine, Takara-machi 13-1, Kanazawa, 920-8640, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Takemura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; 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; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008297:Male; D008482:Mediastinum / Q000473:pathology; D008875:Middle Aged; D009367:Neoplasm Staging; D011013:Pneumonectomy; D012189:Retrospective Studies; D015996:Survival Rate
keywords: Lung cancer surgery; Mediastinal lymph nodes; Metastases (lymph node)