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Next Generation Sequencing for the Detection of Actionable Mutations in Solid and Liquid Tumors
11:15

Next Generation Sequencing for the Detection of Actionable Mutations in Solid and Liquid Tumors

Published on: September 20, 2016

Terminal respiratory unit type lung adenocarcinoma is associated with distinctive EGFR immunoreactivity and EGFR

Michael R Peterson1, Zhe Piao, Lyudmila A Bazhenova

  • 1Department of Pathology, University of California San Diego, School of Medicine, La Jolla, CA, USA.

Applied Immunohistochemistry & Molecular Morphology : AIMM
|August 28, 2007
PubMed

Insights

Epidermal growth factor receptor (EGFR) expression and mutations are key in non-small cell lung cancer. Basal cytoplasmic EGFR positivity was exclusively found in terminal respiratory unit (TRU)-type adenocarcinoma, often with EGFR mutations.

Area of Science:

  • Oncology
  • Molecular Biology
  • Pathology

Background:

  • Non-small cell lung cancer (NSCLC) treatment involves epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, with variable patient response.
  • EGFR mutations are linked to gefitinib response, particularly in non-smokers and women with specific tumor features.
  • Terminal respiratory unit (TRU)-type adenocarcinoma shares characteristics with gefitinib responders, but EGFR expression patterns are not well-documented.

Purpose of the Study:

  • To investigate epidermal growth factor receptor (EGFR) immunoreactivity across various lung cancer types.
  • To correlate EGFR expression patterns with EGFR mutations and terminal respiratory unit (TRU)-type histology.
  • To identify potential biomarkers for EGFR inhibitor therapy response.

Main Methods:

  • Immunohistochemical analysis of EGFR expression in 124 lung resection specimens.
  • Histological classification including identification of TRU-type adenocarcinoma.
  • Detection of EGFR mutations in a subset of cases.

Main Results:

  • EGFR positivity was highest in squamous cell carcinomas (77%), followed by TRU-type adenocarcinomas (63%).
  • A unique basal cytoplasmic EGFR positivity was exclusively observed in TRU-type adenocarcinomas.
  • EGFR mutations were found in 6 of 54 cases, all of which were TRU-type adenocarcinomas and showed positive EGFR immunostaining with basal cytoplasmic localization.

Conclusions:

  • Basal cytoplasmic EGFR immunoreactivity is a distinctive marker for TRU-type adenocarcinoma.
  • This specific EGFR expression pattern is associated with EGFR mutations in a subset of TRU-type adenocarcinomas.
  • Findings suggest potential utility of basal cytoplasmic EGFR positivity as a biomarker for predicting response to EGFR inhibitor therapy in NSCLC.

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