Prognosis of Adjuvant SOX vs XELOX Chemotherapy for Gastric Cancer After D2 Gastrectomy in Chinese Patients

INTRODUCTION: To compare the prognosis of adjuvant SOX (S-1 and oxaliplatin) vs XELOX (capecitabine and oxaliplatin) chemotherapy in Chinese patients with gastric cancer (GC) after D2 gastrectomy. METHODS: This was a real-world study of patients with GC (stages II–III) who underwent D2 gastrectomy and received adjuvant SOX or XELOX between 01/2010 and 06/2017 in Zhongshan Hospital affiliated to Fudan University. The patients were matched by propensity score matching. The primary and secondary endpoints were disease-free survival (DFS) and overall survival (OS), respectively. Adverse events (AEs) were compared. RESULTS: A total of 552 patients were included. The median follow-up time was 24.9 months. There were no differences in DFS (median, 44.4 vs 41.2 months; HR=1.17, 95% CI: 0.92–1.48) and OS (median, 61.5 vs 65.3 months; HR=1.01, 95% CI: 0.73–1.39) between the XELOX and SOX groups. Both DFS and OS had no significant differences between SOX and XELOX for all subgroups based on sex (P=0.949, P=0.990), age (P=0.303, P=0.392), Lauren type (P=0.362, P=0.573), type of gastrectomy (P=0.607 P=0.989), and pathological TNM stage (P=0.899, P=0.888). A total of 86 patients in the SOX subgroup (34.2%) experienced AEs, similar to the rate found in the XELOX subgroup (104 patients or 41.4%; P=0.098). DISCUSSION: The results suggested that adjuvant SOX chemotherapy has similar survival benefits compared to XELOX chemotherapy in Chinese patients with pathological stage II or III GC after D2 gastrectomy.