[A Case of Unresectable Advanced Lower Esophageal Adenocarcinoma That Achieved Pathological Complete Response after Conversion Surgery following Nivolumab plus SOX Therapy].

An 80-year-old woman presented with epigastric discomfort and dysphagia, underwent upper gastrointestinal endoscopy, and was diagnosed with type 2 advanced lower esophageal adenocarcinoma. Computed tomography data revealed that there was the lower esophageal tumor is T3, but a large carina lymph node invading the left bronchus. We diagnosed this patient unresectable cT4bN1M0, cStage ⅣA advanced esophageal adenocarcinoma, and we administered nivolumab plus S-1 plus oxaliplatin(SOX)therapy. After 3 courses of the therapy, imaging showed marked reduction in the size of primary tumor and carina lymph node. We diagnosed partial response(PR)and attempted conversion surgery. Video-assisted thoracoscopic esophagectomy with 2 fields lymphadenectomy was performed. The pathological examination demonstrated no residual tumors and no lymph node metastases, and the histological response of primary tumor was determined to be Grade 3, with a pathological complete response(pCR). Currently, the patient is alive without recurrence for 1 year after surgery.