Salvage Surgery Following Definitive Chemoradiotherapy and Immune Checkpoint Inhibitor Therapy for Locally Advanced Thymic Carcinoma

Surgical resection improves prognosis for thymic carcinoma. Recent phase II trials have indicated the efficacy of immune checkpoint inhibitor therapy in unresectable disease. Here, we report a case of salvage surgery following immune checkpoint inhibitor therapy for an initially unresectable, locally advanced thymic carcinoma in a 67-year-old woman. Computed tomography revealed an anterior mediastinal mass and enlarged anterior mediastinal lymph nodes, diagnosed as an unresectable thymic epithelial tumour, due to suspected invasion into the left main pulmonary artery. Thoracoscopic biopsy confirmed the diagnosis of squamous cell carcinoma with high programmed cell death-ligand 1 expression (90%-100%). Following definitive chemoradiotherapy, the patient received durvalumab, which reduced the primary tumour size and resolved lymphadenopathy, without immune-related adverse events. Salvage surgery was performed without invasion of the great vessels. The patient remained disease-free at 2 years postoperatively. Salvage surgery following immune checkpoint inhibitor therapy may be a viable treatment option for thymic carcinoma with high programmed cell death-ligand 1 expression.