Phase II study of S-1, a novel oral derivative of 5-fluorouracil, in advanced gastric cancer. For the S-1 Cooperative Gastric Cancer Study Group.
OBJECTIVE
To assess the efficacy and safety of S-1, a novel oral fluoropyrimidine derivative, we conducted a multicenter late phase II study in patients with advanced gastric cancer.


METHODS
Fifty-one patients who had received no previous chemotherapy were enrolled. Fifty patients were eligible for efficacy and safety analyses. The overall response was evaluated for the 43 patients who had metastatic lesions. S-1 was administered orally after breakfast and dinner for 28 days, followed by a 14-day break. The dosages were assigned according to the patients' body surface area (BSA): BSA <1.25 m(2), 40 mg; 1.25-1.5 m(2), 50 mg, and BSA > or =1.5 m(2), 60 mg, twice daily.


RESULTS
The overall response to treatment was evaluated as partial response in 19 of the 43 patients (44%; 95% confidence interval 30-59%). The median survival time in all patients was 207 days with 1- and 2-year survival rates of 36.0 and 14.0%, respectively. Grade 3 adverse reactions included decreased hemoglobin values in 2 patients, leukopenia, neutropenia and diarrhea in 1 patient each. No other grade 4 or unexpected adverse reactions were seen.


CONCLUSIONS
S-1 is effective against advanced gastric cancer. This oral treatment is suitable for outpatients because of its mild toxicity. Further therapeutic benefits are likely to be obtained by combining S-1 with other chemotherapeutic agents.
Koizumi
W
W
Department of Gastroenterology, East Hospital, Kitasato University, School of Medicine, Kanagawa, Japan. koizumi@med.kitasato-u.ac.jp
Kurihara
M
M
Nakano
S
S
Hasegawa
K
K
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D004334:Drug Administration Schedule; D004338:Drug Combinations; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010094:Oxonic Acid / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D011725:Pyridines / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D013274:Stomach Neoplasms / Q000188:drug therapy*; D005641:Tegafur / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D016896:Treatment Outcome
D000964:Antimetabolites, Antineoplastic; D004338:Drug Combinations; D011725:Pyridines; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid; D005472:Fluorouracil