Combination chemotherapy of S-1 and low-dose twice-weekly cisplatin for advanced and recurrent gastric cancer in an outpatient setting: a retrospective study.
BACKGROUND
We have reported the efficacy and safety of S-1 combined with low-dose consecutive cisplatin therapy for advanced and recurrent gastric cancer, but the regimen was difficult because daily cisplatin administration was necessary. We have already confirmed that cisplatin of 6 mg/m2 twice-weekly maintained the same protein-bound Pt concentration as that of 3 mg/m2 of cisplatin daily. In the present study, the efficacy and safety of a combination of S-1 and low-dose twice-weekly cisplatin were investigated.


METHODS
The participants were 32 patients treated at our hospital, and all were admitted for the first 2 weeks of therapy. S-1 at 80 mg/m2 daily was administered orally in two divided doses. Cisplatin at 6 mg/m2 was administered by intravenous drip infusion over 30 minutes on 2 days each week, day 1 and day 4. Each treatment cycle consisted of 4 weeks of drug administration followed by a 2-week drug-free period (6 weeks in total).


RESULTS
A total of 146 cycles were administered, with a median of three cycles (range: 1-24) per patient. The results were rated as a complete response in 1 case, partial response in 24 cases and stable disease in 5 cases. The response rate was 78.1% (25/32) and the median survival time was 12.0 months (95% confidence interval (CI) 8.9-15.1 months). The response rate did not differ between previously treated and untreated patients. The one-year survival rate was 48.2% (95% CI 30.3-66.0%). The major adverse reactions were myelosuppression and gastrointestinal symptoms. The total incidence of grade 3 or greater adverse reactions was 15.6% (5/32).


CONCLUSIONS
The combination of S-1 and low-dose twice-weekly cisplatin therapy appears to be highly efficacious and safe and shows promise as a useful treatment strategy, even in outpatient clinics.
Tsuji
Akihito
A
Department of Clinical Oncology, Kochi Health Science Center, Kochi, Japan. a-tsuji@r4.dion.ne.jp
Shima
Yasuo
Y
Morita
Sojiro
S
Uchida
Mizuki
M
Okamoto
Koichi
K
Morita
Masanori
M
Horimi
Tadashi
T
Shirasaka
Tetsuhiko
T
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D002945:Cisplatin / Q000008:administration & dosage / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004338:Drug Combinations; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy*; D010094:Oxonic Acid / Q000008:administration & dosage / Q000009:adverse effects; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000188:drug therapy*; D005641:Tegafur / Q000008:administration & dosage / Q000009:adverse effects
D004338:Drug Combinations; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid; D002945:Cisplatin