title: Rationale for a Minimum Number of Lymph Nodes Removed with Non-Small Cell Lung Cancer Resection: Correlating the Number of Nodes Removed with Survival in 98,970 Patients.
abstract: The benefit of thoracic lymphadenectomy in the treatment of resectable non-small cell lung cancer (NSCLC) continues to be debated. We hypothesized that the number of lymph nodes (LNs) removed for patients with pathologic node-negative NSCLC would correlate with survival.
  
  
  
  The National Cancer Data Base (NCDB) was queried for resected, node-negative, NSCLC patients treated between 2004 and 2014. Patients were grouped according to the number of LNs removed (1-4, 5-8, 9-12, 13-16, and ≥17). Patients with <10 LNs removed were also compared with those with ≥10 LNs removed. A Cox regression analysis was performed and hazard ratios (HRs) calculated, with 95 % confidence intervals (CIs).
  
  
  
  Of 1,089,880 patients with NSCLC reported to the NCDB during the study period, 98,970 (9.0 %) underwent resection without evidence of pathologic nodal involvement. Lobectomy was performed in 83.9 %, sublobar resection was performed in 12.7 % and pneumonectomy was performed in 2.8 % of patients. The number of LNs removed correlated with increasing tumor size and extent of resection. On multivariate analysis, increasing age, male sex, white ethnicity, high tumor grade, larger tumor size, pneumonectomy, and positive surgical margins were all negatively correlated with overall survival. The number of LNs removed and lobectomy/bi-lobectomy correlated with improved survival. The removal of <10 LNs was associated with a 12 % increased risk of death (HR: 1.12, 95 % CI 1.09-1.14; p < 0.001).
  
  
  
  Survival of early-stage NSCLC patients is associated with the number of LNs removed. The surgical management of early-stage NSCLC should include thoracic lymphadenectomy of at least 10 nodes.
authors.affiliation: Department of Surgery, Abington Hospital-Jefferson Health, Abington, PA, USA.
authors.forename: Andres X
authors.initials: AX
authors.lastname: Samayoa
authors.affiliation: Baylor College of Medicine, Houston, TX, USA.
authors.forename: Todd A
authors.initials: TA
authors.lastname: Pezzi
authors.affiliation: Department of Surgery, Abington Hospital-Jefferson Health, Abington, PA, USA. christopher.pezzi@jefferson.edu.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Pezzi
authors.affiliation: American College of Surgeons, Commission on Cancer, Chicago, IL, USA.
authors.forename: E
authors.initials: E
authors.lastname: Greer Gay
authors.affiliation: Department of Surgery, Abington Hospital-Jefferson Health, Abington, PA, USA.
authors.forename: Megumi
authors.initials: M
authors.lastname: Asai
authors.affiliation: Department of Surgery, Abington Hospital-Jefferson Health, Abington, PA, USA.
authors.forename: Nandini
authors.initials: N
authors.lastname: Kulkarni
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Lankenau Medical Center, Wynnewood, PA, USA.
authors.forename: Ned
authors.initials: N
authors.lastname: Carp
authors.affiliation: Department of Radiation Oncology, University of Texas, MD Anderson Comprehensive Cancer Center, Houston, TX, USA.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Chun
authors.affiliation: Department of Thoracic Surgery, Baptist MD Anderson Cancer Center, Jacksonville, FL, USA.
authors.forename: Joe B
authors.initials: JB
authors.lastname: Putnam
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000208:ethnology / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000208:ethnology / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D008197:Lymph Node Excision / Q000706:statistics & numerical data*; D008198:Lymph Nodes / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D011013:Pneumonectomy / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D012737:Sex Factors; D015996:Survival Rate; D013909:Thorax; D047368:Tumor Burden; D014481:United States / Q000453:epidemiology