title: Effective enrichment strategy for EML4-ALK fusion gene screening in patients with non-small cell lung cancer.
abstract: BACKGROUND
  A novel fusion gene that comprises the echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) genes was recently identified in non-small cell lung cancer (NSCLC), particularly in adenocarcinoma. A specific ALK inhibitor has been shown to exert anti-tumor effects in NSCLC with the EML4-ALK fusion gene. Previous reports suggested an EML4-ALK incidence of approximately 5% in a pan-NSCLC population, with an increased frequency in younger patients, but an appropriate strategy for further selecting patients with the EML4-ALK fusion gene remains unknown.
  
  
  METHODS
  Patients, 55 years of age or younger, who were diagnosed with NSCLC without typical squamous cell carcinoma features at our institute were retrospectively evaluated. The tumor specimens were examined by immunohistochemistry for the EML4-ALK fusion gene and by polymerase chain reaction for epidermal growth factor receptor (EGFR) mutations.
  
  
  RESULTS
  Between January 2004 and September 2011, the EML4-ALK fusion gene was detected in 19.6% (9/46) of patients. The fusion gene incidence increased to 31% (9/29) when patients with EGFR mutations were excluded. The EML4-ALK fusion gene was further detected in 2 cases of undifferentiated cell carcinoma.
  
  
  CONCLUSIONS
  EML4-ALK fusion gene examinations could be more effectively performed by selecting young NSCLC patients without EGFR mutations, whereas selection on the basis of a non-smoking or adenocarcinoma history, as reported in previous studies, may not correctly identify the patient groups with potential EML4-ALK fusion gene.
authors.affiliation: Department of Respiratory Medicine, Tohoku University Hospital, 1-1, Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan; Department of Pathology, Tohoku University Hospital, 1-1, Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. Electronic address: m-kobayashi@rm.med.tohoku.ac.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: Department of Respiratory Medicine, Tohoku University Hospital, 1-1, Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. Electronic address: sakatomo@idac.tohoku.ac.jp.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Sakakibara
authors.affiliation: Department of Respiratory Medicine, Tohoku University Hospital, 1-1, Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. Electronic address: akinoue@idac.tohoku.ac.jp.
authors.forename: Akira
authors.initials: A
authors.lastname: Inoue
authors.affiliation: Department of Respiratory Medicine, Miyagi Cancer Center, 47-1, Aishimashiote, Nodayama, Natori 981-1293, Japan. Electronic address: fukuhara-tatsuro@miyagi-pho.jp.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Fukuhara
authors.affiliation: Department of Pathology, Tohoku University Hospital, 1-1, Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. Electronic address: hsasano@patholo2.med.tohoku.ac.jp.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Sasano
authors.affiliation: Department of Respiratory Medicine, Tohoku University Hospital, 1-1, Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. Electronic address: ichinose@rm.med.tohoku.ac.jp.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Ichinose
authors.affiliation: Department of Respiratory Medicine, Tohoku University Hospital, 1-1, Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan; South Miyagi Medical Center, 38-1, Aza-Nishi, Ogawara, Shibata-gun, Miyagi 989-1253, Japan. Electronic address: toshinkw47@gmail.com.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Nukiwa
mesh_terms: D000328:Adult; D000367:Age Factors; D000077548:Anaplastic Lymphoma Kinase; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000235:genetics*; D005260:Female; D050939:Gene Fusion / Q000235:genetics*; D018773:Genes, erbB-1 / Q000235:genetics; D005820:Genetic Testing; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D008297:Male; D008869:Microtubule-Associated Proteins / Q000235:genetics*; D008875:Middle Aged; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D012697:Serine Endopeptidases / Q000235:genetics*
chemical_list: D018797:Cell Cycle Proteins; D008869:Microtubule-Associated Proteins; C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D020794:Receptor Protein-Tyrosine Kinases; C415585:EML4 protein, human; D012697:Serine Endopeptidases
keywords: Driver gene mutation; EML4-ALK fusion gene; Genetic screening; Non-small cell lung cancer