Although several chemotherapy regimens used against advanced gastric cancer (AGC) have been studied extensively in an attempt to further improve the prognosis of patients, to date, no standard chemotherapeutic regimens have been established. The aim of this study was to determine the anti-tumor efficacy and safety of TS-1 or TS-1 plus cisplatin (CDDP).

We treated 78 patients with AGC either with 80 mg/m² of TS-1 for 28 days, which was followed by a 2-week rest, or with 80 mg/m² of TS-1 for 21 days and 60 mg/m² of CDDP on day 8 every 5 weeks.

Tumor response rates in the neoadjuvant chemotherapy group and in the recurrent or post-palliative surgery group were 87.5% and 32.4%, respectively, and they were 28.6% and 48.4%, respectively, in the TS-1 group and the TS-1 plus CDDP group. The survival rates in the recurrent and the post-palliative surgery group were significantly different according to the degree of tumor response (P=0.0016), but the one-year survival rates according to the kinds of regimens (TS-1 or TS-1/CDDP group) were not significantly different. The incidences of grade 3 or 4 adverse effects in the TS-1 and the TS-1/CDDP groups were 14.3% and 36.8%, respectively.

The anti-tumor efficacy and safety of TS-1 and TS-1 plus CDDP in Korean patients with AGC seemed to be high with modest adverse effects, thus suggesting the possible use of this regimen as a standard chemotherapy for gastric cancer.