Salvage Surgery for Epidermal Growth Factor Receptor-Mutant Lung Cancer With Osimertinib Resistance: A Case Report

Recent advancements in lung cancer treatment, including molecular targeted therapies and immune checkpoint inhibitors, have significantly improved patient outcomes and extended survival. However, the efficacy and safety of salvage surgery for lesions resistant to targeted therapy like osimertinib remain poorly understood. This report highlights a case of salvage surgery performed on a patient with epidermal growth factor receptor (<i>EGFR</i>)-mutant lung cancer resistant to osimertinib. A 60-year-old woman was diagnosed with lung adenocarcinoma (cT1cN3M0, cStage IIIB) harboring an <i>EGFR</i> exon 19 deletion (L747-A750>P). Initial treatment with afatinib yielded a favorable tumor response for 18 months, but disease progression ensued. Osimertinib was subsequently initiated after detection of the <i>EGFR</i> T790M mutation, demonstrating initial efficacy. Nineteen months later, regrowth of a lung lesion was observed, although radiographic evaluation showed no lymph node enlargement, with disease confined to the right upper lobe. A robot-assisted right upper lobectomy with lymph node dissection was successfully performed. During surgery, the patient experienced refractory atrial fibrillation, which was successfully managed with defibrillation. Pathological analysis confirmed metastasis to the right upper mediastinal lymph nodes. The <i>EGFR</i> exon 19 deletion mutation was detected in the resected tumor, while the T790M mutation was absent. The patient has remained disease-free for 10 months without additional treatment. Salvage surgery following molecular targeted therapy for lung cancer has been reported to be effective for selected patients. However, the mechanisms of resistance to osimertinib are diverse, and the efficacy of salvage surgery for patients with osimertinib resistance is not well understood. In this case, although the postoperative observation period is still short, salvage lung resection suggests the possibility of leading to favorable disease control. With a thorough evaluation of surgical indications and appropriate management of several complications associated with the prior treatment, salvage surgery can be a valuable and viable option for selected patients.