[A case of cancer successfully treated by chemotherapy of S-1 as first-line chemotherapy].

The patient was an 83-year-old man who had undergone pancreaduodenectomy for a diagnosed lower bile duct cancer in April 2004. CT demonstrated intra-abdominal lymph node enlargement 2 years postoperatively and CA19-9 increased. S-1, an oral fluoropyrimidine anticancer drug, was started as first-line chemotherapy. A complete response was confirmed after the first two courses of S-1 monotherapy. CR persisted for 2 years and S-1 was discontinued after 25th course because of long CR. No grade 3 or more toxicities were noted.