Response to dacomitinib in advanced non-small-cell lung cancer harboring the rare delE709_T710insD mutation: A case report

BACKGROUND Tyrosine kinase inhibitors (TKI) have been the standard first-line therapy for advanced non-small cell lung cancer (NSCLC) of epidermal growth factor receptor (EGFR) sensitive mutations. Uncommon EGFR mutations are increasingly reported with the development of next-generation sequencing. However, their sensitivity to TKIs is variable with limited clinical evidence. CASE SUMMARY Here, we report a patient with the rare delE709_T710insD mutation, who showed the favorable efficacy of dacomitinib and achieved a partial response with a progression-free survival of 7.0 mo. CONCLUSION To our knowledge, this is the first report displaying the clinical efficacy of dacomitinib for patients with delE709_T710insD, which may help to provide alternatives in non-classical variant NSCLC patients. Further studies are warranted to make the optimal choice of EGFR-TKI for rare mutations.