Small Cell Lung Cancer Derived from Adenocarcinoma with Mutant Epidermal Growth Factor Receptor Provides a Signature of Transcriptional Alteration in Tumor Cells

Intern Med. 2019 Nov 15;58(22):3261-3265. doi: 10.2169/internalmedicine.2988-19. Epub 2019 Jul 10.

Abstract

Small cell lung cancer (SCLC) transformation of epidermal growth factor receptor (EGFR) mutant adenocarcinoma (ADC) during EGFR tyrosine kinase inhibitor (TKI) treatment is an example of a rare subset of acquired drug resistance. We herein report the case of a 75-year-old man treated with afatinib who was then diagnosed with SCLC transformation. After two years of successful treatment with afatinib, the tumor relapsed, and a re-biopsy revealed SCLC harboring EGFR exon 19 deletion. We encountered a case of transcriptional alteration, potentially important for SCLC transformation of EGFR mutant lung ADC, that was recognized via the expression of NOTCH, ASCL1 and RB1 on immunohistochemical staining.

Keywords: acquired drug resistance; adenocarcinoma; epidermal growth factor receptor; small cell lung cancer; transcriptional alteration.

Publication types

  • Case Reports

MeSH terms

  • Adenocarcinoma of Lung / drug therapy
  • Adenocarcinoma of Lung / pathology*
  • Afatinib
  • Aged
  • Drug Resistance, Neoplasm / genetics*
  • ErbB Receptors / genetics*
  • Female
  • Humans
  • Lung Neoplasms / drug therapy
  • Lung Neoplasms / pathology*
  • Male
  • Mutation
  • Protein Kinase Inhibitors / therapeutic use
  • Small Cell Lung Carcinoma / drug therapy
  • Small Cell Lung Carcinoma / pathology*

Substances

  • Protein Kinase Inhibitors
  • Afatinib
  • ErbB Receptors