Exploiting Circulating Tumour DNA to Intensify the Postoperative Treatment Resected Colon Cancer Patients

Inclusion Criteria, Part I, adjuvant phase: * Written informed consent to study procedures; * 18 - 70 years of age ECOG Performance Status ≤ 1 or 71-75 years of age with ECOG Performance Status 0; * Histologically confirmed stage III or high-risk stage II adenocarcinoma of colon including intraperitoneal rectal cancer. Stage II colon cancers are defined at high risk if at least one major prognostic factor (pT4, less than 12 nodes examined, clinical presentation with bowel perforation) or at least two minor prognostic factors (grade 3 or 4, clinical presentation with bowel obstruction, histological signs of vascular or lymphatic or perineural invasion, high preoperative CEA levels) are reported; * Curative surgery performed no less than 4 and no more than 12 weeks prior to randomization (pending results of ct-DNA analysis, up to 2 cycles of FOLFOX/CAPOX are allowed to start the adjuvant treatment within 8-10 weeks after surgery); * Contrast-enhanced chest and abdominal CT scan (or abdomen MRI and chest CT if contrast-enhanced CT scan is contraindicated) performed after the surgery and prior to randomization with no evidence of metastatic disease; * Availability of formalin-fixed, paraffin-embedded (FFPE) tumor tissue from the surgical specimen and blood sample for ct-DNA analysis within 28 days prior randomization; * Positive ct-DNA after surgery (central assessment); * Neutrophils ≥1.5 x 109/L, Platelets ≥100 x 109/L, Hgb ≥ 9 g/dl; * Total bilirubin ≤1.5 fold the upper-norma…