[A Case of Advanced Gastric Cancer Confirmed as Pathological Complete Response Following S-1 plus Oxaliplatin Chemotherapy and Gastric Resection].

A 69-year-old woman presented with persistent nauseous, underwent upper gastrointestinal endoscopy, and was diagnosed with type 2 advanced gastric cancer at the antrum. Abdominal contrast CT image data revealed that there was a large, swollen, pancreatic superior lymph node invading the common hepatic artery. We determined that the tumor was unresectable and systemic chemotherapy was performed using S-1 plus oxaliplatin(SOX)therapy. After 5 courses of chemotherapy, the abdominal contrast CT image data indicated reduction of both the primary lesion and lymph node metastasis. A laparotomy was performed. As the No. 8a lymph node was forming hard scar tissue, we could not dissected clearly it from the common hepatic artery wall. We strongly suspected that cancer tissue remained at the artery wall. A distal gastrectomy and Roux-en-Y reconstruction were performed. Histologically, the resected specimen was determined to be Grade 3, with a pathological complete response(pCR). The patient was administered S-1 for 6 months after the operation and has enjoyed 2.5 years of recurrence-free survival. SOX therapy for unresectable gastric cancer and surgical intervention as conversion surgery were effective. This case demonstrated the possibility of life prolongation using these therapies.