MRD-guided Deferred Adjuvant Therapy in Resectable Early-stage Colon Cancer

Inclusion Criteria: Participants must fit all of the following inclusion criteria to be enrolled in this study: 1. Over 18 years old (including 18 years old) and under 70 years old (including 70 years old) when signing the informed consent form; 2. The Eastern Cooperative Oncology Group (ECOG) physical status scores are 0-1 and do not deteriorate within 2 weeks before enrollment. The expected survival time is no less than 12 weeks; 3. Histological or cytological confirmed stage II high-risk and stage III low-risk none high microsatellite instability (MSI-H) colon adenocarcinoma according to the Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) primary tumor, regional nodes, metastasis (TNM) stage (8th edition). High-risk factors for stage II patients include: T4, poorly differentiated histology (high-grade, excluding MSI-H status), vascular invasion, neural invasion, intestinal obstruction or tumor site perforation pre-operation, positive or unknown margins, insufficient margin distance and examined lymph nodes less than 12; Stage III low-risk patients include patients with T1-3 N1 (excluding T4 or N2). 4. No evidence of distant metastasis (distant organ and/or distant lymph node metastasis) confirmed by comprehensive examination; 5. The distal end of the tumor is ≥12cm from the anal edge evaluated by pre-operative endoscopy. If the endoscopy is absent before surgery, the distance could be evaluated by radiology or during the surgery; 6. Patients who have not received neoadjuvant therapy and can achieve R0 radical resection; 7. Sufficient surgical fresh tissue samples for customized personalized MRD testing panels detected by whole exome sequencing (WES); available for preoperative blood, post-operative day (POD) 3-7 blood, and POD 21-30 blood samples for MRD testing; 8. Females of the childbearing period should take appropriate contraceptive measures and should not breastfeed from the screening stage to 3 months post-treatment. Before starting treatment, a negative pregnancy test, or one of the following criteria should be confirmed for no risk of pregnancy: 1. Post-menopause, defined as age greater than 50 years and amenorrhea for at least 12 months after cessation of all exogenous hormone replacement therapy. 2. Women younger than 50 years who have been amenorrhea for 12 months or more after cessation of all exogenous hormone therapy and whose luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels are within laboratory postmenopausal reference values can also be considered as post-menopausal. 3. Have undergone irreversible sterilization surgery, including hysterectomy, bilateral oophorectomy, or bilateral salpingectomy, except bilateral tubal ligation. 9. Male participants should use barrier contraception (i.e., condoms) from the screening stage to 3 months post-treatment; 10. The participants volunteer to join in the study and signed the informed consent in writing; 11. Patients who are suitable for CAPEOX and mFOLFOXIRI adjuvant therapy. Exclusion Criteria: Participants who meet any of the following criteria are not eligible for this study: 1. Received any of the following treatments: 1. Received neoadjuvant therapy in the past; 2. Previously received any systemic chemotherapy or immunotherapy for colon cancer; 3. Previously received any radiotherapy for colon cancer; 4. Undergone colon cancer surgery in the past; 2. Previously or concomitantly diagnosed of other malignant tumors (except for adequately treated cervical carcinoma in situ, basal or squamous cell skin cancer); 3. Patients with other histological types rather than adenocarcinoma (such as neuroendocrine carcinoma, sarcoma, lymphoma, squamous cell carcinoma, etc.); 4. MSI-H/deficient mismatch repair (dMMR) patients; 5. Pathological, clinical, or radiologic evidence of metastatic lesions, including isolated, distant, or discontinuous intra-abdominal metastases; 6. Patients with multiple primary colorectal cancer; 7. Received other parts of open surgery rather than the colon within 14 days prior to the patient's enrollment; 8. Cannot provide surgical tissues for customized personalized MRD testing or fail to customize personalized MRD testing panels. 9. Cannot provide pre-operative blood, POD 3-7 blood, and POD 21-30 for MRD testing. 10. Suffer from other serious diseases that may affect the follow-up and short-term survival according to the judgment of the investigators; 11. Any other medical conditions and social/psychological problems, which make the patient unfit to participate in this study; 12. History of blood transfusion within 2 weeks before surgery or during surgery; 13. Those who cannot afford contrast-enhanced magnetic resonance imaging (MRI) or contrast-enhanced computed tomography (CT) for clinical follow-up; 14. Previously used Chinese patent medicine (CPM) with anti-tumor effect. Those who have used CPM with anti-tumor effect for less than 7 days, and have stopped for over 2 weeks can be enrolled in the study; 15. Have serious or uncontrolled systemic diseases (such as severe mental disease, neurological disease, epilepsy or dementia, unstable or uncompensated respiratory, cardiovascular, hepatic or renal diseases, left ventricular ejection fraction (LVEF) \< 50%, evidence of uncontrolled hypertension \[greater than or equal to CTCAE grade 3 hypertension despite drug therapy\]); patients with dysphagia, active gastrointestinal disease, or other diseases that significantly affect drug absorption, distribution, metabolism, and excretion. Those who have ever undergone major gastrectomy; 16. Fever and body temperature above 38°C within the past 1 week, or active infection with clinical significance. Active tuberculosis. Active fungal, bacterial, and/or viral infections requiring systemic treatment; 17. Those with active bleeding or new thrombotic disease who are taking therapeutic anticoagulant drugs or have bleeding tendency; 18. Th