17. Phase II study of oxaliplatin plus S-1 as neoadjuvant chemotherapy for advanced gastric cancer: Response and safety results

Objective: The efficacy and safety of Oxaliplatin combined with S-1 (SOX regimen) for advanced gastric cancer were investigated.
Methods: Patients with locally advanced adenocarcinoma of the stomach or esophagogastric junction were enrolled. Oxaliplatin was administered i.v. (100 mg/m²) on day 1, while S-1 was administered orally (80 mg/m²/day, b.i.d.) for 14 days every 21 days. Surgery was performed after 2 cycles of SOX.
Results: Between April 2010 and November 2010, 20 patients, of median age 57.7 years (range, 31-74 years), who were clinically staged IIB in 10%, IIIA in 15%, IIIB in 30%, IIIC in 45% according to AJCC 7th edition, were treated with the combination of Oxaliplatin and S-1. After a 2 cycles of chemotherapy, 20 patients were evaluable for response, and underwent surgery (18 had an R0 resection). A total of 13 patients (65.0%) showed downstaging, 3 patients (15.0%) showed complete response and 9 (45.0%) showed partial response making the overall response rate 60.0% (95% CI: 38.5- 81.5%). In 14 patients (6 cases cannot be evaluated for toxicity due to missing data) assessed for safety, the major toxic effects were nausea (57.1%), anorexia (42.9%), fatigue (42.9%), anemia (28.6%), thrombocytopenia (21.4%) and sensory neuropathy (21.4%), the major grade 3 or 4 adverse events include anemia (7.1%). There was no neutropenia fever or treatment-related deaths.
Conclusions: Oxaliplatin and S-1 combination chemotherapy was active and highly tolerable as a neoadjuvant chemotherapy for AGC.