Background: Previous studies on oxaliplatin and fluoropyrimidines as adjuvant therapy in older patients with stage III colon cancer (CC) produced conflicting results. Patients and methods: We assessed the impact of age on time to tumour recurrence (TTR), disease-free survival (DFS), cancer-specific survival (CSS), and overall survival (OS) in 2360 patients with stage III CC (1667 aged <70 years and 693 ≥ 70 years) randomised to receive 3 or 6 months of FOLFOX or CAPOX within the frame of the phase III, TOSCA study. Results: Older patients compared with younger ones presented more frequently an Eastern Cooperative Oncology Group performance status equal to 1 (10.5% vs 3.3%, p < 0.001), a greater number of right-sided tumours (40.9% vs 26.6%,...