title: The number of lymph node metastases as a prognostic factor in patients with N1 non-small cell lung cancer.
abstract: BACKGROUND
  Lymph node (LN) status is an important component of staging; it provides valuable prognostic information and influences treatment decisions. However, the prognostic significance of the number of positive LNs in N1 non-small cell lung cancer (NSCLC) remains unclear. In this study we evaluated whether a higher number of positive LNs results in worse survival among patients with N1 disease.
  
  
  METHODS
  The Surveillance, Epidemiology, and End Results database was used to identify 3,399 patients who underwent resection for N1 NSCLC. Subjects were categorized into groups based on the number of positive nodes: one, two to three, four to eight, and more than eight positive LNs. The prognostic significance of the number of positive LNs in relation to survival was evaluated using the Kaplan-Meier method. Stratified and Cox regression analysis were used to evaluate the relationship between the number of positive LNs and survival after adjusting for potential confounders.
  
  
  RESULTS
  Unadjusted survival analysis showed that a greater number of N1 LNs was associated with worse lung cancer-specific (P < .0001) and overall (P < .0001) survival. Mean lung cancer-specific survival was 8.8, 8.2, 6.0, and 3.9 years for patients with one, two to three, four to eight, and more than eight positive LNs, respectively. Stratified and adjusted analysis also showed the number of N1 LNs was an independent predictor of survival after controlling for potential confounders.
  
  
  CONCLUSIONS
  The number of positive LNs is an independent prognostic factor of survival in patients with N1 NSCLC. This information may be used to further stratify patients with respect to risk of recurrence in order to determine postoperative management.
authors.affiliation: University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, NJ.
authors.forename: Sirisha
authors.initials: S
authors.lastname: Jonnalagadda
authors.affiliation: Division of Hematology and Oncology and Palliative Care Medicine, Mount Sinai School of Medicine, New York, NY.
authors.forename: Cardinale
authors.initials: C
authors.lastname: Smith
authors.affiliation: Division of General Internal Medicine, Mount Sinai School of Medicine, New York, NY.
authors.forename: Grace
authors.initials: G
authors.lastname: Mhango
authors.affiliation: Division of General Internal Medicine, Mount Sinai School of Medicine, New York, NY; Division of Pulmonary and Critical Care Medicine, Mount Sinai School of Medicine, New York, NY. Electronic address: juan.wisnivesky@mssm.edu.
authors.forename: Juan P
authors.initials: JP
authors.lastname: Wisnivesky
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000473:pathology*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D018426:SEER Program; D016019:Survival Analysis