Successful treatment of EGFR-mutated non-small cell lung cancer with reduced-dose gefitinib: A case report.

Epidermal growth factor receptor (EGFR) mutation is a favorable prognostic factor of non-small cell lung cancer (NSCLC). In the majority of patients with EGFR mutations, clinical benefits of EGFR-tyrosine kinase inhibitors (TKIs) have been reported. One of the TKIs, gefitinib, appears to be less toxic to the skin than other TKIs. The present study reports a case of NSCLC with EGFR mutation (exon 19 deletion) in which dose-reduced gefitinib was effective against recurrence. Due to development of a grade 3 skin adverse event (AE) after 2 months of daily administration of gefitinib, the frequency of administration of gefitinib was reduced to every other day for 2 weeks. As the AE continued, the frequency of administration was reduced to once every 3 days. The patient has been in remission for 27 months since treatment with 250 mg gefitinib once every 3 days was initiated, which is the lowest dose to be reported in a successfully treated case of NSCLC with EGFR mutation. Dose reduction of gefitinib might be appropriate for patients with severe AEs and should be considered as a treatment option after 1 or 2 months of regular daily dosing of gefitinib if there is no other satisfactory treatment option.