[A case of curatively resected biliary tract cancer with peritoneal dissemination through effective response to chemotherapy of S-1].

The patient is a 55-year-old woman who has biliary tract cancer with peritoneal dissemination (T3N1P2M0, Stage IV b). Since a curative operation was deemed impossible, we conducted chemotherapy using S-1. S-1 (120 mg/day) was administered for 2 weeks and then chemotherapy was discontinued for 1 week, which was regarded as one course. After 2 courses of the chemotherapy, CT scan showed that the metastatic lymph node and tumor of peritoneal dissemination were reduced in size, and that there was no ascites. Left lobectomy of the liver, cholecystectomy, and partial resection of omentum were carried out. The pathological diagnosis was also curative (pT1, pN0, pP0, Stage I). We think this case shows the possibility of S-1 for patients with unresectable biliary tract cancer.