Adjuvant oxaliplatin with S-1 (SOX) versus S-1 for stage II-III gastric cancer (CAPITAL): A randomized, open-label, phase 3 trial
In brief
Oxaliplatin plus S-1 raises 5-year survival to 71% versus 63%
In a phase 3 trial of 724 patients with stage II-III gastric or gastroesophageal junction cancer after D2 gastrectomy, adding oxaliplatin to S-1 increased 5-year overall survival from 62.9% to 70.9% and improved disease-free survival similarly. The benefit came with higher grade 3-4 toxicity (25% vs 13%), especially neutropenia, highlighting a trade-off clinicians must weigh.
- Journal
- Med (New York, N.Y.) (Q1)
- Published
- 14 August 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Run-Cong Nie, Shi Chen, Jin Wan, Xiao-Wei Sun, Wei-Qin Hong, Hong-Bo Wei, et al.
- PMID
- 42600610
- DOI
- 10.1016/j.medj.2026.101258
Why clinicians should know about it
- Picked for Oncology and Radiation Oncology (paper of the day, 15 August 2026): Phase 3 trial of adjuvant SOX vs S‑1 in gastric
Abstract
BACKGROUND: Adjuvant chemotherapy following D2 gastrectomy constitutes the standard-of-care for resectable gastric or gastroesophageal junction (GEJ) carcinoma. The CAPITAL trial is a multicenter, randomized, phase 3 study, aiming to assess the efficacy and safety of adjuvant oxaliplatin plus S-1 (SOX) versus S-1 alone. METHODS: Patients with histologically confirmed pathological stage II-III gastric or GEJ adenocarcinoma after gastrectomy with D2 lymphadenectomy were randomly assigned (1:1) to receive either the SOX regimen (n = 362) or the S-1 regimen (n = 362). The primary endpoint was overall survival. This study is registered with ClinicalTrials.gov (NCT01795027). FINDINGS: The median follow-up was 74.0 months (interquartile range [IQR], 35.5-89.3). The 5-year overall survival rates were 70.9% (95% confidence interval [CI], 66.0-76.1) in the SOX group and 62.9% (95% CI, 57.8-68.5) in the S-1 group (hazard ratio [HR], 0.74; 95% CI, 0.58-0.95; p = 0.018). The 3- and 5-year disease-free survival rates were 71.2% (95% CI, 66.5-76.3) and 66.2% (95% CI, 61.2-71.6) in the SOX group, as compared with 65.1% (95% CI, 60.2-70.5) and 55.6% (95% CI, 50.4-61.3) in the S-1 group (HR, 0.76; 95% CI, 0.61-0.96). Treatment-related adverse events of grade 3-4 occurred in 87 (25%) of 349 patients in the SOX group and 45 (13%) of 347 patients in the S-1 group. The most common grade 3-4 adverse event was neutropenia, occurring in 44 (13%) of 349 patients in the SOX group and 23 (7%) of 347 patients in the S-1 group. CONCLUSIONS: The addition of adjuvant oxaliplatin to S-1 chemotherapy significantly improved overall survival and disease-free survival in patients with gastric cancer. FUNDING: This research was supported by the National Natural Science Foundation of China (82573092 and 82573387).
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.