[A resected case of advanced gastric cancer after treatment with low-dosage TS-1]

We report a case of advanced gastric cancer that responded well to low-dosage TS-1. A 72-year-old woman was diagnosed as having unresectable advanced gastric cancer with ascites and hydronephrosis in the right kidney. She was treated with chemotherapy using a low-dosage of TS-1 (80 mg/body/day) administered perorally for 4 weeks followed by a drug-free 2 weeks, in six-week cycles. However, she developed weight loss, appetite loss, and stomatitis. We therefore reduced the dosage of TS-1 from 80 mg/body/day to 60 mg/body/day. The ascites and hydronephrosis gradually improved during the following 3 months, whereupon she could undergo total gastrectomy. The postoperative findings showed no ascites and no peritoneal dissemination. The postoperative pathological findings showed that the cancer cells were localized to within the mucosa, and there were no cancer cells in the greater and lesser omentum. Three weeks after the operation, TS-1 was resumed at 60 mg/body/day. However, 3 months later,ascites and metastasis to the abdominal skin developed, and she died 9 months after the operation.