Response to Afatinib in a Patient with NSCLC Harboring Novel EGFR Exon 20 Insertion Mutations

Onco Targets Ther. 2020 Sep 30;13:9753-9757. doi: 10.2147/OTT.S268694. eCollection 2020.


Purpose: Most epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations are resistant to tyrosine kinase inhibitors (TKIs). While some non-small cell lung cancer (NSCLC) patients harboring special subtypes of EGFR ex20ins still achieved clinical response after TKIs treatment, identifying special subtypes of EGFR ex20ins is helpful to find out NSCLC patients who can respond to TKIs.

Case presentation: A 71-year-old non-smoker Chinese female was diagnosed with advanced lung adenocarcinoma harboring EGFR ex20ins (N771delinsKG). The patient received first-line afatinib (40 mg/day) therapy and a significant and substantial reduction in tumor size was observed subsequently. According to RESIST 1.1, a radiological partial response was achieved. The final progression-free survival was 10 months.

Conclusion: This is the first published case report of EGFR N771delinsKG lung adenocarcinoma, which highlighted the heterogeneity of clinical response to TKIs for EGFR ex20ins-mutant NSCLC. Such results need to be further investigated in prospective studies.

Keywords: EGFR exon 20 insertions; afatinib; lung adenocarcinoma; next generation sequencing.

Publication types

  • Case Reports

Grant support

The authors thank the patient for his participation and his agreement to the publication of the report. This work was supported by the Medical Science and Technology Project Foundation of Zhejiang Province of China (2015KYB439) and Scientific Research Fund of Taizhou Science and Technology Agency (1601KY05 and 1801KY19).