[Type 4 advanced gastric cancer responding to histological complete response after neoadjuvant S-1 combined with CDDP therapy-report of a case].

A 75-year-old man with type 4 advanced gastric cancer was referred to our hospital. We diagnosed the tumor as cStage III B(cT4a, cN2, cM0)gastric cancer. We selected neoadjuvant S-1 combined with CDDP therapy for him. After 2 courses of chemotherapy, the extension of the gastric wall improved. After an additional 2 courses of chemotherapy, the primary tumor revealed a partial response(PR), judged from a barium meal study and upper GI endoscopic findings, and a total gastrectomy with lymph node dissection was performed. The pathological specimens showed no cancer cells in the gastric wall and lymph nodes, so the histological effect was judged as Grade 3.