289 Background: In Asia, adjuvant S-1 monotherapy following D2 gastrectomy represents a standard treatment for patients with pathological stage II/III gastric or gastro-oesophageal junction (GEJ) carcinoma. We aimed to assess the efficacy and safety of adjuvant oxaliplatin plus S-1 versus S-1 administered in this setting. Methods: The CAPITAL trial was a multicentre, randomised, open-label, phase 3 study conducted at 13 hospitals in China. Eligible patients were aged 18 years or older with histologically confirmed pathological stage II-III gastric or GEJ adenocarcinoma after gastrectomy with D2 lymph node dissection, with an Eastern Cooperative Oncology Group (ECOG) performance status score of 0-2. Patients were randomly assigned (1:1) to receive SOX regimen (6 cycles of S-1 40-60 mg orally twice daily for 2 weeks in each 3-week cycle and oxaliplatin 100 mg/m 2 administered intravenously once every 3 weeks, followed by 10 additional cycles of S-1), or S-1 regimen (16 cycles of S-1 at a dose of 40-60 mg twice per day for 2 weeks, followed by a rest of 1 week). The primary endpoint was overall survival in the intention-to-treat population. Safety analysis were done in patients who received at least one dose of the trial drug. This study is registered with ClinicalTrials.gov, NCT01795027. Results: Between Oct 28, 2011 and Nov 3, 2017, 724 patients were randomly assigned to receive either adjuvant SOX (n=362) or adjuvant S-1 (n=362). By the clinical cutoff date of Nov 3, 2022, the median follow-up time was 74.0 months (IQR 35.5-89.3). The 5-year overall survival were 70.9% (95% CI 66.0-76.1) in the SOX group and 62.9% (57.8-68.5) in the S-1 group. The HR for death in the SOX group, as compared with the S-1 group, was 0.74 (0.58-0.95; p=0.018). The 3 and 5-year disease-free survival were 71.2% (66.5-76.3) and 66.2% (61.2-71.6) in the SOX group, as compared with 65.1% (60.2-70.5) and 55.6% (50.4-61.3) in the S-1 group. The HR of disease-free survival for the SOX group versus the S-1 group was 0.76 (0.61-0.96; p=0.021). Treatment-related adverse events of any grade occurred in 295 (85%) of 349 patients in the SOX group and 260 (75%) of 347 patients in the S-1 group. The most common grade 3-4 adverse events was neutropenia (44 (13%) of 349 patients in the SOX group and 23 (7%) of 347 patients in the S-1 group). No treatment-related deaths were recorded. Conclusions: The addition of oxaliplatin to S-1 chemotherapy significantly improved both overall survival and disease-free survival in patients with stage II-III gastric or GEJ adenocarcinoma. SOX regimen should be considered as a standard adjuvant treatment option for this patient population following D2 gastrectomy. Clinical trial information: NCT01795027 .
Nie et al. (2026) studied this question.