Afatinib for an EGFR exon 20 insertion mutation: A case report of progressive stage IV metastatic lung adenocarcinoma with 54 months' survival

Asia Pac J Clin Oncol. 2018 Mar;14 Suppl 1:7-9. doi: 10.1111/ajco.12853.


Non-small cell lung cancers (NSCLC) harboring the uncommon epidermal growth factor receptor (EGFR) exon 20 insertion mutations are generally thought to be unresponsive to EGFR-tyrosine kinase inhibitor (TKI) therapy. Presented here is a case of stage IV NSCLC harboring an uncommon EGFR exon 20 insertion mutation that was maintained at minimal progressive disease for 54 months, with 36 months on the second-generation TKI afatinib. Contrary to the existing literature, the patient in this case demonstrated a long, durable response to the EGFR-TKI, which was exhibited by a long survival endpoint. This suggests that stability in clinical symptoms might be sufficient to warrant continuation of therapy.

Keywords: EGFR exon 20 insertion; afatinib; epidermal growth factor receptor (EGFR); irreversible EGFR inhibitor; tyrosine kinase inhibitor (TKI); uncommon EGFR mutation.

Publication types

  • Case Reports

MeSH terms

  • Adenocarcinoma / drug therapy*
  • Adenocarcinoma / mortality
  • Adenocarcinoma of Lung
  • Afatinib
  • Exons / genetics*
  • Female
  • Humans
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / mortality
  • Middle Aged
  • Mutation
  • Neoplasm Metastasis
  • Quinazolines / administration & dosage
  • Quinazolines / pharmacology
  • Quinazolines / therapeutic use*
  • Survival Analysis
  • Time Factors


  • Quinazolines
  • Afatinib