Adjuvant Chemotherapy With S-1 Plus Docetaxel Versus S-1 Plus Oxaliplatin in Stage III Gastric Cancer

Abstract

Background/Aim: The Japanese Gastric Cancer Treatment Guidelines recommend doublet chemotherapy (S-1 plus another chemotherapy) over S-1 alone for patients with pStage III gastric cancer who underwent radical gastrectomy. However, no consensus exists on adjuvant regimens for patients with pStage III gastric cancer. Therefore, we conducted a comparative study to evaluate the tolerability, safety, and survival outcomes of docetaxel plus S-1 (DS) and S-1 plus oxaliplatin (SOX) therapies as adjuvant chemotherapy for patients with pStage III gastric cancer. Patients and Methods: We retrospectively collected data from consecutive patients with gastric cancer who underwent gastrectomy and received DS or SOX therapies postoperatively at the Osaka International Cancer Institute between December 2016 and December 2021. We conducted a propensity score matching analysis to balance clinical backgrounds. Results: Eighty patients who met the eligibility criteria were analyzed. After matching, 40 patients were included in the study (20 each in the DS and SOX groups). No significant adverse events were observed. The mean ratios of the delivered dose to the planned dose were 74.1% and 86.6% for S-1 and docetaxel in the DS group, respectively, and 75.8% and 76.9% for S-1 and oxaliplatin in the SOX group, respectively. No significant differences were found in recurrence-free and overall survival between the DS and SOX groups (p=0.688 and p=0.772, respectively). Conclusion: DS and SOX therapies as adjuvants were safe and manageable for patients with pStage III gastric cancer who underwent radical gastrectomy. No significant differences were found in prognosis between the two therapies.