title: Does Lymph Node Count Influence Survival in Surgically Resected Non-Small Cell Lung Cancer?
abstract: BACKGROUND
  The prognostic significance of the number of lymph nodes sampled (NLNS) during resection for non-small cell lung cancer (NSCLC) is unclear. The NLNS is influenced by many factors, and some have argued that it should be a surrogate for quality. We sought to determine the influence of the NLNS on overall survival and cancer-specific survival for surgically resected NSCLC.
  
  
  METHODS
  The California Cancer Registry was queried from 2004 to 2011 for cases of stage I to III NSCLC treated with surgical resection, identifying 16,393 patients. Kaplan-Meier and Cox proportional hazards modeling were used to determine the influence of NLNS on overall survival and cancer-specific survival.
  
  
  RESULTS
  In all, 15,195 patients had information regarding nodal sampling. Eighty percent (13,167 of 15,195) were treated with lobectomy. Patients who were younger, male, non-Hispanic white, highest socioeconomic status, higher stage, or larger size tumor had more nodes removed. Sampling fewer than 10 nodes was associated with poorer overall survival when compared with sampling 10 or more nodes after adjustment for demographic and clinical factors for stage I: overall survival hazard ratio 1.78 (95% confidence interval: 1.54 to 2.05, p < 0.0001), hazard ratio 1.43 (95% confidence interval: 1.27 to 1.59, p < 0.0001), and hazard ratio 1.16 (95% confidence interval: 1.05 to 1.28, p = 0.004), for 0, 1 to 3, and 4 to 10 nodes, respectively. Of patients who underwent sublobar resection, 43.8% had no nodes sampled.
  
  
  CONCLUSIONS
  For NSCLC, the NLNS influenced both overall survival and cancer-specific survival, but the influence is dependent on stage. Surgeons should perform mediastinal lymphadenectomy to maximize patient survival, but the optimal NLNS remains unclear.
authors.affiliation: Section of General Thoracic Surgery, UC Davis Medical Center, Sacramento, California; Heart Lung Vascular Center, David Grant Medical Center, Travis AFB, California. Electronic address: eadavid@ucdavis.edu.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: David
authors.affiliation: Section of General Thoracic Surgery, UC Davis Medical Center, Sacramento, California.
authors.forename: David T
authors.initials: DT
authors.lastname: Cooke
authors.affiliation: Department of Public Health Sciences, UC Davis School of Medicine, Davis, California.
authors.forename: Yingjia
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Georgetown University School of Medicine, Washington, DC.
authors.forename: Kieranjeet
authors.initials: K
authors.lastname: Nijar
authors.affiliation: Division of Surgical Oncology, Department of Surgery, UC Davis Medical Center, Sacramento, California.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Canter
authors.affiliation: Department of Public Health Sciences, UC Davis School of Medicine, Davis, California; Public Health Institute, Cancer Registry of Greater California, Sacramento, California.
authors.forename: Rosemary D
authors.initials: RD
authors.lastname: Cress
mesh_terms: D000368:Aged; D002140:California / Q000453:epidemiology; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000556:secondary / Q000601:surgery*; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008197:Lymph Node Excision / Q000379:methods*; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008482:Mediastinum; D009367:Neoplasm Staging; D011013:Pneumonectomy; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends