[Long‒Term Complete Response after Salvage Radiotherapy with Nivolumab Following Mediastinoscopic Esophagectomy in a High‒Risk Elderly Patient with Advanced Esophageal Cancer].

Neoadjuvant chemotherapy followed by radical esophagectomy is the standard treatment for advanced esophageal cancer in Japanese treatment guideline. However, in elderly patients with dysphagia and impaired organ function, preoperative chemotherapy may worsen their condition. We report here a case of a 79‒year‒old malnourished man with advanced esophageal squamous cell carcinoma and EGJ adenocarcinoma presenting with severe dysphagia. Given his age, frailty, and high‒risk of systemic decline, initial mediastinoscopic esophagectomy was selected over neoadjuvant therapy. Pathology showed a positive radial margin and PD‒L1 expression, prompting postoperative local salvage radiotherapy(40 Gy/20 fr)with nivolumab(480 mg/4 weeks). After 4 cycles, nivolumab was discontinued due to immune‒related pneumonitis, and S‒1 chemotherapy was initiated. Nearly 2 years postoperatively, the patient remains recurrence‒free. This case demonstrates the feasibility of a personalized, minimally invasive treatment strategy with tailored adjuvant therapy in high‒risk elderly patients.