title: Immunohistochemistry as a screening tool for ALK rearrangement in NSCLC: evaluation of five different ALK antibody clones and ALK FISH.
abstract: OBJECTIVE
  ALK FISH analysis is used as the reference standard to demonstrate ALK rearrangements, which qualify patients with pulmonary adenocarcinomas for therapy with ALK inhibitors. The aim of this study was to find screening ALK antibody clones with the best positive and best negative percentage agreement with ALK FISH.
  
  
  RESULTS
  Three hundred and three pulmonary adenocarcinomas were evaluated with ALK FISH and stained with five ALK antibody clones (5A4; D5F3; ALK1; ALK01; SP8) with standardized detection systems. D5F3 was additionally assessed using the OptiView enhanced detection and amplification system. ALK FISH found 14 cases (4.6%) that harboured ALK rearrangements. These stained at all intensities for D5F3 and 5A4. To identify rearranged cases among stained cases, we subsequently analysed all immunohistochemically positive cases with ALK FISH.
  
  
  CONCLUSIONS
  D5F3 with OptiView exclusively stained rearranged cases with strong intensity, without a single false-positive or false-negative case. The number of subsequent ALK FISH analyses required would have decreased from 303 to 14 cases (-95.4%), reducing significantly the time, work and costs without any loss of diagnostic quality and accuracy.
authors.affiliation: Department of Pathology, University Hospital and Paracelsus Medical University Salzburg, Salzburg, Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Hutarew
authors.forename: Cornelia
authors.initials: C
authors.lastname: Hauser-Kronberger
authors.forename: Felix
authors.initials: F
authors.lastname: Strasser
authors.forename: Ida C
authors.initials: IC
authors.lastname: Llenos
authors.forename: Otto
authors.initials: O
authors.lastname: Dietze
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D000328:Adult; D000368:Aged; D000077548:Anaplastic Lymphoma Kinase; D000818:Animals; D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D002289:Carcinoma, Non-Small-Cell Lung / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D008175:Lung Neoplasms / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology; D008297:Male; D051379:Mice; D008875:Middle Aged; D009154:Mutation; D011237:Predictive Value of Tests; D011817:Rabbits; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; C000626173:ALK protein, human; C000626174:Alk protein, mouse; D000077548:Anaplastic Lymphoma Kinase; D020794:Receptor Protein-Tyrosine Kinases
keywords: ALK FISH; ALK antibody clones; ALK mutations in non-small-cell lung cancer; EML4-ALK rearrangement; immunohistochemical screening for ALK rearrangements