title: S-1 for the treatment of gastrointestinal cancer.
abstract: BACKGROUND
  5-Fluorouracil (5-FU)-based regimens are used worldwide as the standard treatment in chemotherapy for gastric cancer. S-1 , a fourth-generation oral fluoropyrimidine that combines tegafur and two biochemical modulators: gimeracil and oteracil potassium, is now attracting considerable interest.
  
  
  METHODS
  This review addresses the clinical evidence of S-1 in gastrointestinal malignancies, such as gastric, colorectal, pancreatic and biliary tract cancers. S-1 has demonstrated advantages over standard therapies, in both advanced and postoperative settings, in large Phase III studies. S-1 alone or S-1 plus cisplatin is recommended in the 2010 Gastric Cancer Treatment Guidelines, by the Japanese Gastric Cancer Association. Results from Phase III studies have demonstrated that S-1 in combination with chemotherapies, such as cisplatin in gastric cancer, and irinotecan and oxaliplatin in colorectal cancers, is non-inferior to conventional 5-FU-based standard regimens, with the benefit of convenience and reduced toxicity.
  
  
  CONCLUSIONS
  The excellent design of S-1 aimed to reduce toxicity by avoiding certain routes of degradation, and to enhance activity by reducing catabolism. This has provided not only a suitable alternative to 5-FU, but also higher efficacy.
authors.affiliation: Osaka University Graduate School of Medicine, Department of Frontier Science for Cancer and Chemotherapy, 2-2 Yamadaoka, Suita City, Osaka, 565-0871, Japan. taroh@cfs.med.osaka-u.ac.jp
authors.forename: Taroh
authors.initials: T
authors.lastname: Satoh
authors.forename: Yuh
authors.initials: Y
authors.lastname: Sakata
mesh_terms: D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives; D002945:Cisplatin / Q000008:administration & dosage; D004338:Drug Combinations; D005472:Fluorouracil / Q000627:therapeutic use; D005770:Gastrointestinal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D000077146:Irinotecan; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D000077150:Oxaliplatin; D010094:Oxonic Acid / Q000009:adverse effects / Q000627:therapeutic use*; D017410:Practice Guidelines as Topic; D005641:Tegafur / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000964:Antimetabolites, Antineoplastic; D004338:Drug Combinations; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid; D000077146:Irinotecan; D002945:Cisplatin; D005472:Fluorouracil; D002166:Camptothecin