title: Management of adjuvant S-1 therapy after curative resection of gastric cancer: dose reduction and treatment schedule modification.
abstract: BACKGROUND
  The aim of this study was to determine the optimal management of adjuvant S-1 therapy for stage II or III gastric cancer, encompassing the details of dose reduction and treatment schedule modification.
  
  
  METHODS
  We retrospectively examined 97 patients with stage II or III gastric cancer who received S-1 chemotherapy following gastrectomy between January 2003 and December 2007. S-1 (80 mg/m² per day) was orally administered twice daily for 4 weeks, followed by a 2-week rest. As a rule, treatment was continued for 1 year after gastrectomy. Dose reduction or treatment schedule modification was performed according to toxicity profiles.
  
  
  RESULTS
  Among the 97 patients, 57 (59%) underwent dose reduction at least once and 39 (40%) received treatment schedule modification. Of the 57 patients who required dose reduction, 45 (79%) underwent reduction within 3 months of the beginning of treatment. The most common reasons for dose reduction were anorexia (47%), followed by diarrhea (32%), leukopenia (24%), and rash (16%), with the reasons overlapping. Although the difference in the requirement for dose reduction was not significant, patients with a low creatinine clearance level or those who underwent total gastrectomy had a greater tendency to require dose reduction. The duration of the S-1 treatment period was at least 3 months in 88% of the patients, at least 6 months in 82%, and the planned 1-year period in 73% of the patients.
  
  
  CONCLUSIONS
  In most patients, the planned 1-year adjuvant S-1 therapy for stage II or III gastric cancer could be completed by modifying the dose reduction and treatment schedule.
authors.affiliation: Gastrointestinal Oncology Division, National Cancer Center Hospital, Chuo-ku, Tokyo, 104-0045, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Iwasa
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Yamada
authors.forename: Takeo
authors.initials: T
authors.lastname: Fukagawa
authors.forename: Takako
authors.initials: T
authors.lastname: Eguchi Nakajima
authors.forename: Ken
authors.initials: K
authors.lastname: Kato
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hamaguchi
authors.forename: Shinji
authors.initials: S
authors.lastname: Morita
authors.forename: Makoto
authors.initials: M
authors.lastname: Saka
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Katai
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shimada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage* / Q000009:adverse effects; D017024:Chemotherapy, Adjuvant; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004338:Drug Combinations; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010094:Oxonic Acid / Q000008:administration & dosage* / Q000009:adverse effects; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000601:surgery; D005641:Tegafur / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D000964:Antimetabolites, Antineoplastic; D004338:Drug Combinations; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid