[A case of advanced cancer of the gastric remnant with complete response to S-1 plus docetaxel chemotherapy as confirmed histopathologically].

A 64-year-old man underwent a probe laparotomy for unresectable gastric remnant cancer (GRC) involving the pancreas and retroperitoneum. Combination chemotherapy with S-1 and docetaxel was given after surgery. Computed tomography and endoscopy showed tumor shrinkage after two courses of chemotherapy. After 6 courses, endoscopic examination revealed a small ulcer. Although no cancer cells were found in a biopsy specimen, we were unable to conclude that such cells had disappeared completely. The patient underwent resection of GRC with pancreatosplenectomy. The remnant stomach could not be dissected from the pancreas, and we suspected the presence of residual cancer cells. The tumor was found to have had a complete response (CR) to combination chemotherapy on histopathological examination.