1. ¹Department of Gastroenterology, Saitama Cancer Centre, 818 Komuro, Ina-machi, Kitaadachi-gun, Saitama 362-0806, Japan
2. ²Division of Gastroenterology, Institute of Medicine, University of Tsukuba, Ibaraki, Japan
3. ³Department of Gastroenterology and Medical Oncology, Kitasato University East Hospital, Kanagawa, Japan
4. ⁴Division of Digestive Endoscopy and Gastrointestinal Oncology, National Cancer Centre Hospital East, Chiba, Japan
5. ⁵Department of Clinical Oncology, Hiroshima University Graduate School of Medicine, Hiroshima, Japan
6. ⁶Department of Medical Oncology, Hokkaido University Graduate School of Medicine, Hokkaido, Japan
7. ⁷Division of Internal Medicine, Niigata Cancer Centre Hospital, Niigata, Japan
8. ⁸Department of Gastroenterology, Aomori Prefectural Centre Hospital, Aomori, Japan
9. ⁹Department of Internal Medicine, Gunma Prefectural Cancer Centre, Gunma, Japan
10. ¹⁰Department of Internal Medicine, Misawa Municipal Hospital, Aomori, Japan
11. ¹¹Department of Gastroenterology, Saku Central Hospital, Nagano, Japan
12. ¹²Department of Chemotherapy, Tokyo Metropolitan Komagome Hospital, Tokyo, Japan
13. ¹³Second Department of Internal Medicine, Osaka Medical College, Osaka, Japan
14. ¹⁴First Department of Internal Medicine and Department of Medicine and Biosystemic Science, Graduate School of Medicine, Kyushu University, Fukuoka, Japan
15. ¹⁵Department of Cancer Chemotherapy, National Kyushu Cancer Centre, Fukuoka, Japan
16. ¹⁶Department of Endoscopy, Faculty of Medicine, University of the Ryukyu, Okinawa, Japan

Correspondence: Dr K Yamaguchi, E-mail: k-yamaguchi@cancer-c.pref.saitama.jp

Received 22 March 2006; Revised 3 May 2006; Accepted 3 May 2006.

Abstract

The aims of this phase I/II study of docetaxel and S-1 were to determine the dose-limiting toxicity (DLT), maximum-tolerated dose (MTD), and recommended dose (RD) in the phase I part and to explore the tumour response, survival and safety in the phase II part. Patients with histologically- or cytologically confirmed unresectable or recurrent gastric cancer were eligible. Treatment consisted of intravenous docetaxel on day 1 (starting dose 50 mg m^-2) and oral S-1 at a fixed dose of 40 mg m^-2 twice daily on days 1–14, every 4 weeks up to six cycles. Nine patients took part in the phase I portion of the study. The MTD of docetaxel was determined to be 50 mg m^-2, with the DLTs of grade 3 infection associated with grade 3 neutropenia and grade 4 neutropenia during S-1 administration. The RD of docetaxel was 40 mg m^-2 in combination with S-1 40 mg m^-2 b.i.d. The efficacy and safety of this regimen was therefore assessed in 46 patients with at least one measurable lesion. The overall response rate and estimated median overall survival were 46% (95% CI, 31–61%) and 14.0 months (8.3–17.3 months), respectively. The most common grade 3/4 toxicity was neutropenia (67% of patients), which was predictable and manageable. This regimen showed promising activity with moderate toxicities in advanced gastric cancer.