title: Comparison of outcomes for patients with lepidic pulmonary adenocarcinoma defined by 2 staging systems: A North American experience.
abstract: OBJECTIVE
  Application of the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) classification of lepidic adenocarcinomas in conjunction with American Joint Committee on Cancer (AJCC) staging has been challenging. We aimed to compare IASLC/ATS/ERS and AJCC classifications, to determine if they could be integrated as a single staging system.
  
  
  METHODS
  We reviewed patients from 2001-2013 who had AJCC stage I lepidic adenocarcinomas, and categorized them according to IASLC/ATS/ERS guidelines: adenocarcinoma in situ (AIS); minimally invasive adenocarcinoma (MIA); or invasive adenocarcinoma (IA). We integrated the 2 classification systems by separating AIS and MIA as being stage 0, and routinely classifying IA as stage I.
  
  
  RESULTS
  Median follow-up was 52 months in 138 patients. The IASLC/ATS/ERS classification demonstrated a higher disease-free survival (DFS) in AIS (100%) and MIA (96%) versus IA (80%) (P = .022), and higher overall survival (OS): 100% for AIS and MIA, versus 90% for IA (P = .049). The AJCC classification identified a DFS of 87% and an OS of 94% for stage I patients. Integration of the 2 systems demonstrated higher DFS in stage 0 (98%) versus I (80%) (P = .006), and higher OS: 100% for stage 0 versus 90% for stage I (P = .014).
  
  
  CONCLUSIONS
  The IASLC/ATS/ERS classification better discriminates AIS and MIA compared with current AJCC staging; however, integration suggests that these categories may be collectively classified in AJCC staging, based on similarly favorable outcomes and distinctive survival rates.
authors.affiliation: Division of Thoracic Surgery, Swedish Cancer Institute, Seattle, Wash.
authors.forename: Candice L
authors.initials: CL
authors.lastname: Wilshire
authors.affiliation: Division of Thoracic Surgery, Swedish Cancer Institute, Seattle, Wash. Electronic address: brian.louie@swedish.org.
authors.forename: Brian E
authors.initials: BE
authors.lastname: Louie
authors.affiliation: CellNetix Pathology and Laboratories, Seattle, Wash.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Horton
authors.affiliation: Division of Thoracic Surgery, Swedish Cancer Institute, Seattle, Wash.
authors.forename: Massimo
authors.initials: M
authors.lastname: Castiglioni
authors.affiliation: Division of Thoracic Surgery, Swedish Cancer Institute, Seattle, Wash.
authors.forename: Ralph W
authors.initials: RW
authors.lastname: Aye
authors.affiliation: Division of Thoracic Surgery, Swedish Cancer Institute, Seattle, Wash.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Farivar
authors.affiliation: Division of Medical Oncology, Swedish Cancer Institute, Seattle, Wash.
authors.forename: Howard L
authors.initials: HL
authors.lastname: West
authors.affiliation: Division of Thoracic Surgery, Swedish Cancer Institute, Seattle, Wash.
authors.forename: Jed A
authors.initials: JA
authors.lastname: Gorden
authors.affiliation: Division of Thoracic Surgery, Swedish Cancer Institute, Seattle, Wash.
authors.forename: Eric
authors.initials: E
authors.lastname: Vallières
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008168:Lung / Q000473:pathology* / Q000601:surgery; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome; D014861:Washington
keywords: lung cancer surgery; lung cancer: biology; lung cancer: diagnosis; lung pathology; pathology