title: Adjuvant Chemotherapy After Lobectomy for T1-2N0 Non-Small Cell Lung Cancer: Are the Guidelines Supported?
abstract: BACKGROUND
  Evidence guiding adjuvant chemotherapy (AC) use after lobectomy for stage I non-small cell lung cancer (NSCLC) is limited. This study evaluated the impact of AC use and tumor size on outcomes using a large, nationwide cancer database.
  
  
  METHODS
  The effect of AC on long-term survival among patients who underwent lobectomy for margin-negative pathologic T1-2N0M0 NSCLC in the National Cancer Data Base from 2003 to 2006 was estimated using the Kaplan-Meier method. The specific tumor size threshold at which AC began providing benefit was estimated with multivariable Cox proportional hazards modeling.
  
  
  RESULTS
  Overall 3,496 of 34,360 patients (10.2%) who met inclusion criteria were treated with AC, although AC use increased over time from 2003, when only 2.7% of patients with tumors less than 4 cm and 6.2% of patients with tumors of 4 cm or larger received AC. In unadjusted survival analysis, AC was associated with a significant 5-year survival benefit for patients with tumors less than 4 cm (74.3% vs 66.9%; P<.0001) and 4 cm or greater (64.8% vs 49.8%; P<.0001). In subanalyses of patients grouped by strata of 0.5-cm increments in tumor size, AC was associated with a survival advantage for tumor sizes ranging from 3.0 to 8.5 cm.
  
  
  CONCLUSIONS
  Use of AC among patients with stage I NSCLC has increased over time but remains uncommon. The results of this study support current treatment guidelines that recommend AC use after lobectomy for stage I NSCLC tumors larger than 4 cm. These results also suggest that AC use is associated with superior survival for patients with tumors ranging from 3.0 to 8.5 cm in diameter.
authors.affiliation: From the Departments of Surgery and Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina; and the Department of Cardiothoracic Surgery, Stanford University School of Medicine, Palo Alto, California.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Speicher
authors.affiliation: From the Departments of Surgery and Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina; and the Department of Cardiothoracic Surgery, Stanford University School of Medicine, Palo Alto, California.
authors.forename: Lin
authors.initials: L
authors.lastname: Gu
authors.affiliation: From the Departments of Surgery and Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina; and the Department of Cardiothoracic Surgery, Stanford University School of Medicine, Palo Alto, California.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Wang
authors.affiliation: From the Departments of Surgery and Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina; and the Department of Cardiothoracic Surgery, Stanford University School of Medicine, Palo Alto, California.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Hartwig
authors.affiliation: From the Departments of Surgery and Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina; and the Department of Cardiothoracic Surgery, Stanford University School of Medicine, Palo Alto, California.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: D'Amico
authors.affiliation: From the Departments of Surgery and Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina; and the Department of Cardiothoracic Surgery, Stanford University School of Medicine, Palo Alto, California. From the Departments of Surgery and Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina; and the Department of Cardiothoracic Surgery, Stanford University School of Medicine, Palo Alto, California.
authors.forename: Mark F
authors.initials: MF
authors.lastname: Berry
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000401:mortality / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011013:Pneumonectomy; D017410:Practice Guidelines as Topic; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents