Randomized Trial of Plasma ctDNA Methylation-Guided Adjuvant Therapy in T4N0 and Low-Risk Stage III Colorectal Cancer

The patient (T4N0 or low-risk stage III) will be randomly assigned to either the control group (FOLFOX/CAPOX for 3 months) or the intervention group (FOLFOX/CAPOX for 6 months or FOLFOX/CAPOX for 3 months followed by FOLFIRI/CAPIRI for 3 months) to receive adjuvant therapy. Venous blood samples (8-16 mL) will be collected at 1 month, 3 months, and 6 months after surgery for dynamic monitoring of plasma ctDNA.