title: ALK rearrangement in a large series of consecutive non-small cell lung cancers: comparison between a new immunohistochemical approach and fluorescence in situ hybridization for the screening of patients eligible for crizotinib treatment.
abstract: BACKGROUND
  Echinoderm microtubule associated proteinlike 4-anaplastic lymphoma receptor tyrosine kinase (EML4-ALK) translocation has been described in a subset of patients with non-small cell lung cancer (NSCLC) and has been shown to have oncogenic activity. Fluorescence in situ hybridization (FISH) is used to detect ALK-positive NSCLC, but it is expensive, time-consuming, and difficult for routine application.
  
  
  OBJECTIVE
  To evaluate the potential role of immunohistochemistry (IHC) as a screening tool to identify candidate cases for FISH analysis and for ALK inhibitor therapy in NSCLC.
  
  
  METHODS
  We performed FISH and IHC for ALK and mutational analysis for epidermal growth factor receptor (EGFR) and KRAS in 523 NSCLC specimens. We conducted IHC analysis with the monoclonal antibody D5F3 (Ventana Medical Systems, Tucson, Arizona) and a highly sensitive detection system. We also performed a MassARRAY-based analysis (Sequenom, San Diego, California) in a small subset of 11 samples to detect EML4-ALK rearrangement.
  
  
  RESULTS
  Of the 523 NSCLC specimens, 20 (3.8%) were positive for ALK rearrangement by FISH analysis. EGFR and KRAS mutations were identified in 70 (13.4%) and 124 (23.7%) of the 523 tumor samples, respectively. ALK rearrangement and EGFR and KRAS mutations were mutually exclusive. Of 523 tumor samples analyzed, 18 (3.4%) were ALK(+) by IHC, 18 samples (3.4%) had concordant IHC and FISH results, and 2 ALK(+) cases (0.3%) by FISH failed to show ALK protein expression. In the 2 discrepant cases, we did not detect any mass peaks for the EML4-ALK variants by MassARRAY.
  
  
  CONCLUSIONS
  Our results show that IHC may be a useful technique for selecting NSCLC cases to undergo ALK FISH analysis.
authors.affiliation: From the Units of Pathological Anatomy (Drs Alì, Proietti, Lupi, and Sensi and Ms Pelliccioni), Pneumology (Dr Chella), Endoscopic Section of Pneumology (Dr Ribechini), and Thoracic Surgery (Drs Melfi and Lucchi), Azienda Ospedaliera Universitaria Pisana, Pisa, Italy; the Units of Pathological Anatomy (Ms Niccoli and Drs Giannini, Borrelli, and Fontanini) and Thoracic Surgery (Dr Mussi), Department of Surgical, Medical, Molecular Pathology and Critical Area, University of Pisa, Pisa, Italy; Diatech Pharmacogenetics, Jesi, Italy (Dr Menghi); and the Department of Oncology, Istituto Toscano Tumori, Ospedale Civile, Livorno, Italy (Dr Cappuzzo).
authors.forename: Greta
authors.initials: G
authors.lastname: Alì
authors.forename: Agnese
authors.initials: A
authors.lastname: Proietti
authors.forename: Serena
authors.initials: S
authors.lastname: Pelliccioni
authors.forename: Cristina
authors.initials: C
authors.lastname: Niccoli
authors.forename: Cristiana
authors.initials: C
authors.lastname: Lupi
authors.forename: Elisa
authors.initials: E
authors.lastname: Sensi
authors.forename: Riccardo
authors.initials: R
authors.lastname: Giannini
authors.forename: Nicla
authors.initials: N
authors.lastname: Borrelli
authors.forename: Maura
authors.initials: M
authors.lastname: Menghi
authors.forename: Antonio
authors.initials: A
authors.lastname: Chella
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ribechini
authors.forename: Federico
authors.initials: F
authors.lastname: Cappuzzo
authors.forename: Franca
authors.initials: F
authors.lastname: Melfi
authors.forename: Marco
authors.initials: M
authors.lastname: Lucchi
authors.forename: Alfredo
authors.initials: A
authors.lastname: Mussi
authors.forename: Gabriella
authors.initials: G
authors.lastname: Fontanini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000077548:Anaplastic Lymphoma Kinase; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000235:genetics; D000077547:Crizotinib; D005260:Female; D015321:Gene Rearrangement; D018773:Genes, erbB-1; D005820:Genetic Testing; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics*; D008297:Male; D008869:Microtubule-Associated Proteins / Q000235:genetics; D008875:Middle Aged; D009154:Mutation; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D011720:Pyrazoles / Q000627:therapeutic use*; D011725:Pyridines / Q000627:therapeutic use*; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000235:genetics; D018631:ras Proteins / Q000235:genetics
chemical_list: D018797:Cell Cycle Proteins; C117307:KRAS protein, human; D008869:Microtubule-Associated Proteins; D047428:Protein Kinase Inhibitors; D011518:Proto-Oncogene Proteins; D011720:Pyrazoles; D011725:Pyridines; D000077547:Crizotinib; C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D020794:Receptor Protein-Tyrosine Kinases; C415585:EML4 protein, human; D012697:Serine Endopeptidases; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins