Treating Choroidal Metastases and Improving Vision with Osimertinib in EGFR T790M-Mutated Lung Adenocarcinoma: A Case Report and Review of the Literature

A 41-year-old never-smoking female was diagnosed with epidermal growth factor receptor (EGFR)-mutated T2bN3M1b lung adenocarcinoma with axillary lymph nodes. She complained of blurred vision in the left eye (2/60) and was subsequently found to have a left choroidal metastasis. Treatment with tyrosine kinase inhibitor (TKI) erlotinib was started, and after 1 year of disease stability, she developed unsteadiness and worsening visual disturbance (1/60). Brain imaging showed 24 new brain metastases, which were treated with Gamma Knife stereotactic radiosurgery. An enlarging axillary lymph node was biopsied, which identified the T790M mutation, and she commenced the novel TKI osimertinib. Three weeks later, her choroidal lesion had regressed from 3.1 mm to 2.2 mm, and after 2 months of osimertinib, her visual acuity had improved to 6/9. At the last follow-up 8 months after initiation of osimertinib, her choroidal metastasis remains stable, and visual acuity has improved to 6/6. Evidence suggests that osimertinib's efficacy in treating cerebral metastases is superior to that of chemotherapy and other EGFR-TKIs (gefitinib and erlotinib); however, the literature is sparse with regards to the use of osimertinib for the treatment of intraocular disease. In this case, the need for intense daily radiation treatment with its associated toxicities was negated, and as such we propose that osimertinib may be a promising treatment for choroidal metastasis secondary to EGFR-mutated lung adenocarcinoma.