[Preoperative combination chemotherapy with TS-1 is effective in a case gastric cancer with peritoneal dissemination]

We report a case of peritoneal cancer dissemination with Type 4 gastric cancer, successfully treated with combination chemotherapy with TS-1. The patient was a 59-year-old female, who complained of abdominal distension with pain, weight loss, and poor appetite. She was diagnosed as unresectable Type 4 gastric cancer, T3N2MOHOP1CY1M0, Stage IV with massive ascites (cytology: Class V). After 2 courses of combined chemotherapy with TS-1 and cisplatin (CDDP), primary tumor reduction was confirmed and no cancer cells were detected from a pathological investigation with biopsied specimens by endoscopy. As additional therapy for remained ascites, intraperitoneal administration of paclitaxel and docetaxel was performed, resulting in a remarkable decrease of ascites with cytological disappearance of cancer cells. The patients underwent total gastrectomy with lymph node dissection, pathological diagnosis of primary site and lymph nodes showed grade 2 effect, and no cancer cells were detected in ascites and peritoneum, microscopically. While she died of peritoneal recurrence after the surgery, the case suggested the clinical advantage of controlling the advanced cancer-bearing state by combination chemotherapy with TS-1, instead of surgery.