title: Log odds of positive lymph nodes are superior to other measures for evaluating the prognosis of non-small cell lung cancer.
abstract: BACKGROUND
  To evaluate the ability of the log odds of positive lymph nodes to predict prognosis in patients with non-small cell lung cancer (NSCLC).
  
  
  METHODS
  Correlations between the log odds of positive lymph nodes, numbers of dissected lymph nodes, dissected lymph node stations, positive lymph nodes, positive lymph node ratio, and positive lymph node stations were retrospectively evaluated using Pearson correlation coefficients (r), survival analysis by Kaplan-Meier, Cox hazard ratio model, and log-rank tests.
  
  
  RESULTS
  The numbers of dissected lymph nodes, positive lymph nodes, dissected lymph node stations and positive lymph node stations significantly correlated with the log odds of positive lymph nodes (P < 0.001, P < 0.001, P = 0.002 and P < 0.001, respectively). The five-year survival ratio of postoperative patients with the log odds of positive lymph nodes <11.412 and >-1.412 were 63.9% and 32.5%, respectively (P < 0.001). According to multivariate analysis, age and log odds of positive lymph nodes are independent risk factors for overall survival (hazard ratio = 2.660, 95% confidence interval 2.114-3.346, P < 0.001). A new staging system featuring a combination of log odds of positive lymph nodes and a tumor node metastasis (TNM) staging system was established for predicting survival.
  
  
  CONCLUSIONS
  The log odds of positive lymph nodes are superior to the positive lymph node ratio and p-N-stage for predicting prognosis of NSCLC. A new staging system that combines log odds of positive lymph nodes and the current TNM staging system predicts prognosis more accurately than the TNM system alone.
authors.affiliation: Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital Tianjin, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Lv
authors.affiliation: Department of Thoracic Surgery, Provincial Hospital affiliated to Shandong University Jinan, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.affiliation: Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital Tianjin, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
keywords: Log odds; non-small cell lung cancer; staging system