[A Case of Advanced Gastric Cancer with Peritoneal Dissemination Effectively Treated with S-1 and Docetaxel Combination Chemotherapy].

A 72-year-old man underwent surgery for advanced gastric cancer. Systemic chemotherapy was started, using a regimen of S-1/CDDP for 4 courses, followed by 8 courses of S-1. Three years and 8 months after the surgery, abdominal CT demonstrated ascites, and the serum CA19-9 level was abnormally high (1,165.1 U/mL). Adenocarcinoma cells were found in the ascites. Treatment with S-1/docetaxel (DOC) was started. After 10 courses, the ascites disappeared and the serum CA19-9 value returned to normal. Four years and 7 months after the operation, the patient has been in good health, with no signs of recurrence.