title: The International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society grading system has limited prognostic significance in advanced resected pulmonary adenocarcinoma.
abstract: The International Association for the Study of Lung Cancer, the American Thoracic Society and the European Respiratory Society (IASLC/ATS/ERS) system which subclassifies lung adenocarcinoma into five distinct types has been widely adopted. We assessed the prognostic value of subclassifying adenocarcinoma in this way in consecutive patients undergoing surgery.
  
  
  
  All patients at our institution undergoing surgery for lung carcinoma between 2000 and 2010 were identified. The original pathology slides were independently reviewed and reclassified according to the 2011 IASLC/ATS/ERS grading and the American Joint Committee on Cancer (AJCC) 7 edition 2009 staging systems.
  
  
  
  We identified 270 patients including 152 with adenocarcinoma histology with long-term follow-up. Using the Kaplan-Meier method, the calculated 5 year survival for each of the adenocarcinoma categories were papillary-predominant 80%, lepidic-predominant 71%, micropapillary-predominant 55%, acinar-predominant 43%, solid-predominant 39% and invasive mucinous adenocarcinoma 38%. The AJCC stage was a very strong predictor of survival (p<0.001). The IASLC/ATS/ERS subclassification of adenocarcinoma demonstrated a trend as a prognostic marker but failed to reach statistical significance in univariate or multivariate analysis.
  
  
  
  Although the IASLC/ATS/ERS classification has been validated by several studies in stage I tumours, further studies of larger cohorts will be required to show prognostic value in unselected lung carcinoma undergoing surgery with curative intent.
authors.affiliation: *Sydney Medical School, Sydney †Cancer Diagnosis and Pathology Research Group, Kolling Institute of Medical Research, Royal North Shore Hospital, St Leonards ‡HistoPath Pathology, North Ryde §Departments of Anatomical Pathology, and ||Cardiothoracic Surgery, Royal North Shore Hospital, St Leonards, New South Wales, Australia ¶these two authors contributed equally.
authors.forename: Darin D
authors.initials: DD
authors.lastname: Westaway
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Toon
authors.forename: Mahtab
authors.initials: M
authors.lastname: Farzin
authors.forename: Loretta
authors.initials: L
authors.lastname: Sioson
authors.forename: Nicole
authors.initials: N
authors.lastname: Watson
authors.forename: Peter W
authors.initials: PW
authors.lastname: Brady
authors.forename: David
authors.initials: D
authors.lastname: Marshman
authors.forename: Manu M
authors.initials: MM
authors.lastname: Mathur
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Gill
mesh_terms: D000230:Adenocarcinoma / Q000145:classification* / Q000401:mortality / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000145:classification* / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading / Q000379:methods*; D017410:Practice Guidelines as Topic; D011379:Prognosis