Efficacy of afatinib treatment for lung adenocarcinoma harboring exon 18 delE709_T710insD mutation

Jpn J Clin Oncol. 2019 Aug 1;49(8):786-788. doi: 10.1093/jjco/hyz086.


Exon 18 delE709_T710insD is an extremely rare mutation in epidermal growth factor receptor (EGFR) in non-small-cell lung cancer (NSCLC); the efficacy of EGFR tyrosine kinase inhibitors against this mutation remains unclear. In this case report, we report a case of NSCLC harboring EGFR exon 18 delE709_T710insD that was not detected by a commercially available assay, but was detected by a next-generation sequencing cancer panel. A 56-year old female patient with advanced NSCLC was diagnosed as EGFR-mutation-negative using the PNAClamp method. ALK rearrangement was also absent and she received cytotoxic chemotherapies. Clinical characteristics, including adenocarcinoma histology and no history of smoking, implied the presence of a driver mutation, so a next-generation-sequencing Oncomine® Cancer Research Panel was conducted in the patient's clinical course and the EGFR exon 18 delE709_T710insD mutation was detected. The patient started afatinib as sixth-line treatment and her pulmonary lesion significantly decreased in size. Afatinib was continued for 7 months until disease progressed.

Keywords: EGFR, exon 18 delE709_T710insD; next-generation sequencing; non-small-cell lung cancer.

Publication types

  • Case Reports

MeSH terms

  • Adenocarcinoma of Lung / diagnostic imaging
  • Adenocarcinoma of Lung / drug therapy*
  • Adenocarcinoma of Lung / genetics*
  • Afatinib / therapeutic use*
  • Aged
  • ErbB Receptors / genetics
  • Exons / genetics*
  • Female
  • Humans
  • Lung Neoplasms / diagnostic imaging
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / genetics*
  • Lung Neoplasms / pathology
  • Male
  • Middle Aged
  • Mutation / genetics*
  • Protein Kinase Inhibitors / therapeutic use
  • Quinazolines / therapeutic use
  • Tomography, X-Ray Computed
  • Treatment Outcome


  • Protein Kinase Inhibitors
  • Quinazolines
  • Afatinib
  • EGFR protein, human
  • ErbB Receptors