[Combination chemotherapy of S-1 and CPT-11 for advanced recurrent gastric cancer]

We performed combination chemotherapy using S-1 and CPT-11 for advanced and recurrent stomach carcinoma in order to study the clinical efficacy thereof. The subjects comprised 13 patients aged 55 to 78 with a PS of 0 to 2, who had histologically confirmed unresectable stomach carcinoma or who had undergone a non curative resection with postoperative recurrence, all having measurable or assessable lesions with no severe damage in the principal organ, and from whom informed consent in writing had been obtained. 80 to 120 mg/day of S-1 were orally administered daily for 21 days according to the body surface area. 60 mg/m2 of CPT-11 was administered on Days 1 and 15. After the administration of S-1 for 3 weeks, from 1- to 2-week-long drug holidays were provided, thereby establishing a total of 4 to 5 weeks as 1 course. This was repeated as many times as possible. Thirteen subjects were registered during the period from November 2001 to February 2004. The details thereof are as follows: 9 male subjects and 4 female subjects with a median age of 65 years, wherein 1 subject had a PS of 0, 3 subjects had a PS of 1, and 9 subjects had a PS of 2. The results for all of the subjects showed that 5 subjects had PR, and the response rate was 38%. Grade 3 or higher adverse events consisted of leucopenia in 38.5%, neutropenia in 46.2%, anemia in 15.4%, and diarrhea in 7.7%. The median survival time (MST) for all of the subjects was 259 days. Specifically, the MST was 248 days for the subjects with a PS of 2 for whom 2 drugs were concomitantly used, and it was equal or longer for the subjects with a PS of 2 who were treated under the sole regimen of S-1. A review of this study showed that side effects were more frequently observed in the subjects with a PS of 2 than in those with a PS of 0 to 1. Furthermore, the average number of courses that were administered to the subjects with a PS of 0 to 1 was 8.5, against 3.6 courses on average in subjects with a PS of 2, thus showing a significant difference between the 2 groups. According to the above results, it is believed that there is a difference in the tolerability of the anticancer drugs between subjects with a PS of 0 to 1 and those with a PS of 2. It is also considered necessary to adjust the dosage of the anticancer drugs and the dosing period for patients with a PS of 2 when preparing a chemotherapeutic regimen for digestive carcinoma, including stomach carcinoma. The present regimen will be further studied to evaluate its potential use after second-line therapy for advanced and recurrent stomach carcinoma.