Unexpected Hair Growth Induced by Gefitinib Treatment in Two Patients with EGFR Gene Mutation-Positive Adenocarcinoma of the Lung

Gefitinib, an EGFR tyrosine kinase inhibitor used for treating EGFR mutation-positive non-small cell lung cancer, was reported to cause unexpected hair growth in two male patients with stage IV adenocarcinoma. Both patients, who achieved complete remission with gefitinib as first-line chemotherapy, experienced significant hair growth: one with more solid and darker hair on the scalp, and the other with new hair growth in a previously bald area. This side effect suggests that gefitinib and similar EGFR-TKIs might have potential therapeutic applications for treating alopecia, as EGFR plays a crucial role in hair follicle development and growth.