This Phase II/III trial will evaluate the what kind of chemotherapy to recommend to patients based on the presence or absences of circulating tumor DNA (ctDNA) after surgery for colon cancer.
1. The patient must have an ECOG performance status of 0 or 1.
2. Patients must have histologically/pathologically confirmed colon adenocarcinoma (T1-3, N1/N1c) with R0 resection accordingly to AJCC 8th edition criteria.
3. No radiographic evidence of overt metastatic disease within 28 days prior to study entry
1. Colon cancer histology other than adenocarcinoma (i.e., neuroendocrine carcinoma, sarcoma, lymphoma, squamous cell carcinoma, etc.).
2. Pathologic, clinical, or radiologic overt evidence of metastatic disease. This includes isolated, distant, or non-contiguous intra-abdominal metastases, even if resected.
3. Tumor-related bowel perforation.
This study contains two cohorts, the ctDNA negative cohort and the ctDNA positive cohort based on the post-operation ctDNA test results. A randomized phase II/III study will be conducted within each cohort. Cohort A: patients will be randomized into immediate treatment arm (Arm 1) and delayed treatment arm (Arm 2). The primary endpoint for phase II of Cohort A is time to ctDNA (+ve) status (TTPos) and the primary endpoint for phase III of Cohort A is disease-free survival. Patients on Arm 2 who turned ctDNA (+ve) will cross over to Cohort B study. Cohort B (ctDNA +ve): patients will be randomized to receive either FP (5-FU/ capecitabine + oxaliplatin, Arm 3) or FOLFIRINOX (5-FU + oxaliplatin + irinotecan, Arm 4) for 6 months. The primary endpoint for both phase II and III of Cohort B is disease-free survival.