A single-arm, phase II feasibility study of neoadjuvant docetaxel, oxaliplatin, and S-1 (DOS) chemotherapy in potentially resectable gastric or gastroesophageal junction adenocarcinoma.
96 Background: The aim of this study was to evaluate feasibility and safety of neoadjuvant docetaxel, oxaliplatin, and S-1 (DOS) chemotherapy in patients with potentially resectable adenocarcinoma of stomach or gastroesophageal junction. Methods: Forty-one patients with clinical stage T3-4N0M0 or T2-4N+M0 determined by CT, endoscopic ultrasonography, and laparoscopy were enrolled between DEC 2008 and MAR 2010. Gastrectomy with D2 lymph node dissection was conducted after 3 cycles of DOS chemotherapy. DOS chemotherapy consists of docetaxel 50 mg/m2 iv (day1), oxaliplatin 100 mg/m2 iv (day1), and S-1 40 mg/m2 po bid (days1-14) at 3 weeks interval. After curative gastrectomy, the patients were given 1 year of adjuvant chemotherapy with S-1 (40 mg/m2 D1-28, every 6 weeks). Results: All patients finished the planned neoadjuvant chemotherapy. Twenty-three (56%) patients achieved a partial response, and the remaining 18 patients had stable disease by CT scan after 3 cycles of DOS chemotherapy. No disease progression was observed during the neoadjuvant chemotherapy. A median 4.7 weeks (range, 4.0-7.6) after the start of the 3rd cycle of DOS chemotherapy, 39 (95%) patients underwent R0 resection with no pathologic residual disease in 4 (10%) patients. Hematologic toxicities were common including grade 4 neutropenia (32%), grade 3 thrombocytopenia (17%), and febrile neutropenia (10%). However, hematologic toxicities were generally transient and manageable. There were no grade 3 or 4 non-hematologic toxicities with frequency > 5% of patients. With all toxicities taken together, 21 (51%) patients experienced grade 3 or 4 toxicities (except grade 3 neutropenia). There was no treatment-related death, and surgical complications included only mild wound problem in 4 (10%) patients. Conclusions: In this study, neoadjuvant DOS chemotherapy could induce a sufficient down-staging and R0 resection of locally advanced gastric cancer with mild and manageable toxicities. A phase III randomized trial is planned for evaluating the benefit of neoadjuvant DOS chemotherapy in patients with locally advanced gastric cancer. [Table: see text]