A novel, highly sensitive ALK antibody 1A4 facilitates effective screening for ALK rearrangements in lung adenocarcinomas by standard immunohistochemistry

J Thorac Oncol. 2015 Apr;10(4):713-6. doi: 10.1097/JTO.0000000000000427.

Abstract

Introduction: Successful treatment of lung cancer patients with crizotinib depends on the accurate diagnosis of anaplastic lymphoma receptor tyrosine kinase (ALK) gene rearrangements. The approved fluorescence in-situ hybridization test is complex and difficult to use in daily diagnostic practice. Immunohistochemical assays-rapid and perfectly adapted for routine pathology practice-have been proposed as alternatives. We evaluated the novel high affinity ALK 1A4 antibody for routine diagnostics in formalin fixed, paraffin-embedded tumor specimens.

Methods: Detection of ALK protein expression was investigated by comparing the new 1A4 antibody and the established D5F3 antibody/Ventana system in 218 lung cancer specimens with known ALK status preanalyzed by quantitative reverse transcription-polymerase chain reaction and fluorescence in-situ hybridization (20 ALK-positive cases, 198 ALK-negative cases).

Results: The accuracy of both immunohistochemical assays for the detection of ALK rearrangements was high. Using a conventional staining procedure without signal enhancement, the 1A4 antibody assay identified all 20 ALK-rearranged tumors (100% sensitivity) and correctly characterized 196 of 198 negative cases (99.1% specificity). The D5F3/Ventana assay detected 19 ALK-rearranged tumors and typed 217 of 218 tumors correctly (95% sensitivity, 99.5 % specificity).

Conclusions: The novel 1A4 antibody represents a promising candidate for screening lung tumors for the presence of ALK rearrangements.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / diagnosis
  • Adenocarcinoma / genetics*
  • Adenocarcinoma / immunology
  • Adenocarcinoma of Lung
  • Anaplastic Lymphoma Kinase
  • Antibodies, Neoplasm / immunology*
  • DNA, Neoplasm / genetics*
  • Gene Expression Regulation, Neoplastic*
  • Gene Rearrangement
  • Humans
  • Immunohistochemistry / methods*
  • In Situ Hybridization, Fluorescence
  • Lung Neoplasms / diagnosis
  • Lung Neoplasms / genetics*
  • Lung Neoplasms / immunology
  • Receptor Protein-Tyrosine Kinases / genetics
  • Receptor Protein-Tyrosine Kinases / immunology*
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Antibodies, Neoplasm
  • DNA, Neoplasm
  • ALK protein, human
  • Anaplastic Lymphoma Kinase
  • Receptor Protein-Tyrosine Kinases