Phase II feasibility study of adjuvant chemotherapy with docetaxel/cisplatin/S-1 followed by S-1 for stage III gastric cancer

Background: This study aimed to evaluate the feasibility, safety, and efficacy of postoperative adjuvant chemotherapy with docetaxel/cisplatin/S-1 (DCS) following S-1 therapy in patients with stage III gastric cancer after curative gastrectomy. Methods: Patients with stage Ill gastric cancer who underwent D2 gastrectomy were enrolled. Adjuvant chemotherapy was initiated within 8 weeks of gastrectomy. The first cycle of chemotherapy consisted of S-1 monotherapy (day 1-14), followed by a 7-day rest period. Cycles 2 and 3 consisted of the following: S-1 (day 1-14) administration, followed by a 14-day rest period, and an intravenous infusion of cisplatin and docetaxel on days 1 and 15. After two cycles, S-1 was administered for up to 1 year. Results: Thirty patients were enrolled between 2014 and 2017. Febrile neutropenia of grade 3 or higher was the most common hematological toxicity with 4 patients (13.3%). Other hematological toxicities of grade 3 or higher were as follows: neutropenia in 3 (10.0%), leukopenia in 3 (10.0%), and anemia in 2 (6.7%) patients. Most frequent non-hematological toxicity of grade 3 was anorexia (n = 4, 13.3%) and general fatigue (n = 3, 10.0%); no grade 4 non-hematological toxicities were observed. Twenty-five patients (833%) completed two cycles of DCS treatment and 18 (60.0%) completed subsequent S-1 treatment for 1 year. The relative dose intensity of docetaxel and cisplatin was 0.86 and that of S-1 was 0.88. Conclusion: The DCS regimen can be acceptable as an adjuvant chemotherapy and offers an effective postoperative treatment option for stage III gastric cancer patients.