title: Risk factors for 6-month continuation of S-1 adjuvant chemotherapy for gastric cancer.
abstract: BACKGROUND
  The factors that affect the 6-month continuation of adjuvant chemotherapy with S-1 have not been fully evaluated. The objective of this retrospective study was to clarify the risk factors for 6-month continuation of S-1 adjuvant chemotherapy.
  
  
  METHODS
  The study selected patients who underwent curative D2 surgery for gastric cancer, were diagnosed with stage 2 or 3 disease, had a serum creatinine level of ≤ 1.2 mg/dl, and received adjuvant S-1 between June 2002 and March 2011.
  
  
  RESULTS
  One hundred of these patients were eligible for the present study. A comparison of 6-month continuation of S-1 stratified by various clinical factors, using the log-rank test, revealed a marginally significant difference in creatinine clearance (CCr) between those patients who continued for 6 months and those who did not. A CCr of 60 ml/min was regarded as the critical point. Uni- and multivariate Cox's proportional hazard analyses demonstrated that CCr was the only significant independent factor for the prediction of 6-month continuation. The 6-month continuation rate was 72.9 % in the patients with CCr ≥ 60 ml/min, and 40.0 % in patients with CCr <60 ml/min (P = 0.015). Adverse events occurred more frequently and earlier in the patients with CCr <60 ml/min than in those with CCr ≥ 60 ml/min.
  
  
  CONCLUSIONS
  CCr <60 ml/min was a significant risk factor for 6-month continuation of S-1 adjuvant chemotherapy, even though the renal function was judged as normal by the serum creatinine level. Careful attention is therefore required for S-1 continuation in patients with CCr <60 ml/min.
authors.affiliation: Department of Gastrointestinal Surgery, Kanagawa Cancer Center, 1-1-2 Nakao, Asahi-ku, Yokohama, 241-0815, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Aoyama
authors.forename: Takaki
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hayashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kuwabara
authors.forename: Yo
authors.initials: Y
authors.lastname: Mikayama
authors.forename: Takashi
authors.initials: T
authors.lastname: Ogata
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Cho
authors.forename: Akira
authors.initials: A
authors.lastname: Tsuburaya
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D003404:Creatinine / Q000032:analysis / Q000097:blood; D004338:Drug Combinations; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010094:Oxonic Acid / Q000009:adverse effects / Q000627:therapeutic use*; D010349:Patient Compliance; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D015996:Survival Rate; D005641:Tegafur / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D004338:Drug Combinations; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid; D003404:Creatinine