Severe Drug-Induced Interstitial Lung Disease Following Administration of Osimertinib as Adjuvant Treatment for Resected EGFR-Mutated Non-Small Cell Lung Cancer: A Case Report

Osimertinib administration has been approved as an adjuvant treatment after complete surgical resection in patients with epidermal growth factor receptor-mutated non-small cell lung cancer. This paper presents the first report of life-threatening postoperative osimertinib-induced interstitial lung disease. An 83-year-old male patient underwent right upper lobectomy (pathological stage IIA) and osimertinib (80 mg/day) was initiated on postoperative day 75. On day 44 of osimertinib administration, chest computed tomography revealed diffuse ground-glass opacities; accordingly, osimertinib-induced interstitial lung disease was diagnosed. Steroid pulse therapy was initiated using a high-flow nasal cannula to treat dyspnea and hypoxemia, rapidly improving the respiratory status and imaging findings; moreover, the patient’s clinical course was excellent. This case report demonstrates that the postoperative occurrence of severe osimertinib-induced interstitial lung disease is a crucial factor that must be considered in patient decision-making regarding perioperative treatment.