Real-world outcomes of Adjuvant De Gramont versus Xelox chemotherapy in reSected gasTric cancER: a propensity score-matched analysis (ASTER study)

The role of adjuvant chemotherapy (aCT) in gastric and esophago-gastric junction cancer (GC/EGJC) remains controversial. This study (ASTER study) aimed to compare the clinical outcomes of De Gramont (DG) versus XELOX/FOLFOX (OXA) regimens in a European real-world setting. This retrospective, bicentric study included patients treated with aCT between January 2001 and January 2018. A propensity score-matched (PSM) analysis was performed to compare oncological outcomes between DG and OXA regimens. Primary endpoints were disease-free survival (DFS) and overall survival (OS). Statistical analyses included the chi-square test, Kaplan-Meier method, and Cox proportional hazards modeling. Among 255 patients (127 DG, 128 OXA), 160 were matched (80 per arm) by PSM. Median DFS and OS did not differ significantly between groups (mDFS: 102.3 vs. 85.4 months, p = 0.91; mOS: 119.5 vs. 89.8 months, p = 0.69). In PSM-adjusted analysis, DG showed a trend towards longer DFS (p = 0.052) and significantly improved OS (p = 0.016). Multivariate analysis confirmed age, ECOG PS, resection margins, and stage as major prognostic factors. DG and OXA regimens demonstrated similar efficacy in the adjuvant treatment of resected GC/GEJC in a European cohort. Further prospective studies are warranted to optimize regimen selection and refine patient stratification.