title: Comparison of clinical characteristics between patients with ALK-positive and EGFR-positive lung adenocarcinoma.
abstract: BACKGROUND
  The discovery of the chromosomal fusion product of anaplastic lymphoma kinase (ALK) with echinoderm microtubule-associated protein-like 4 (EML4) (EML4-ALK) has changed the treatment paradigm of lung cancer. In this study, we analysed the clinical characteristics, including bronchoscopic findings, of patients with EML4-ALK-positive adenocarcinoma and compared them with those of EGFR mutation-positive patients.
  
  
  METHODS
  In this retrospective cohort study, the clinical characteristics and bronchoscopic findings of patients with ALK fusion-positive lung cancers were compared to patients with EGFR-mutant lung cancers.
  
  
  RESULTS
  Among the 440 patients with adenocarcinoma of lung screened for this study, 46 (10.4%) harboured the EML4-ALK fusion, 90 (20.4%) harboured an activating EGFR mutation, and all had adenocarcinoma. In univariate analysis, ALK-positive patients were significantly younger than EGFR-positive patients (p = 0.004) and were more commonly male (p = 0.021). An initial status of stage IV metastatic cancer was more frequently noted in EML4-ALK-positive patients (p = 0.012), with initial brain metastasis frequently observed (p = 0.007). Compared with EGFR-positive patients, EML4-ALK-positive patients were significantly more likely to have positive bronchoscopic findings, which suggested a more centralized origin (p = 0.001). EML4-ALK patients also had significantly more positive bronchoscopic findings and were more commonly male in multivariate analysis.
  
  
  CONCLUSIONS
  The EML4-ALK fusion defines a new molecular subset of NSCLC that has distinct clinical and bronchoscopic findings suggesting more proximal origin when compared to tumours harbouring EGFR mutations.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam 463-707, South Korea.
authors.forename: Hyo Jae
authors.initials: HJ
authors.lastname: Kang
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam 463-707, South Korea; Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Hyo-Jeong
authors.initials: HJ
authors.lastname: Lim
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam 463-707, South Korea; Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Jong Sun
authors.initials: JS
authors.lastname: Park
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam 463-707, South Korea; Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Young-Jae
authors.initials: YJ
authors.lastname: Cho
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam 463-707, South Korea; Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Ho-Il
authors.initials: HI
authors.lastname: Yoon
authors.affiliation: Department of Pathology, Seoul National University Bundang Hospital, Seongnam 463-707, South Korea.
authors.forename: Jin-Haeng
authors.initials: JH
authors.lastname: Chung
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam 463-707, South Korea; Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam 463-707, South Korea; Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea. Electronic address: ctlee@snu.ac.kr.
authors.forename: Choon-Taek
authors.initials: CT
authors.lastname: Lee
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000473:pathology* / Q000556:secondary; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000077548:Anaplastic Lymphoma Kinase; D001999:Bronchoscopy; D066246:ErbB Receptors / Q000235:genetics; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology* / Q000556:secondary; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009154:Mutation / Q000235:genetics; D009367:Neoplasm Staging; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D012189:Retrospective Studies
chemical_list: C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D066246:ErbB Receptors; D020794:Receptor Protein-Tyrosine Kinases
keywords: Bronchoscopy; EGFR; EML4-ALK; Lung adenocarcinoma