Circulating Tumor DNA Guided Adjuvant Chemotherapy for Colon Cancer

Inclusion criteria

• Age: 18 to 75
• Colon adenocarcinoma confirmed by pathology (including high and high differentiated tubular adenocarcinoma, papillary adenocarcinoma, low differentiated adenocarcinoma, mucinous adenocarcinoma and signet ring cell carcinoma)
• Postoperative pathology is stage II with high-risk factors or stage III;

High risk stage II refers to stage II colon cancer with at least one of the following:

a) T4 stage; b) The number of lymph nodes detected was less than 12; c) Poor differentiation (except MSI-H); d) Complicated with LVI or PNI；e) Complicated with obstruction or perforation.

• No distant metastasis was found in preoperative imaging examination and operation;
• ECOG score: 0-2 points;
• MSS/pMMR and BRAF wild type
• Start time of chemotherapy is less than 2 months from the operation
• Have sufficient organ functions;
• The baseline blood routine and biochemical indexes of the subject meet the following standards:

• hemoglobin ≥ 9.0 g / dl;
• absolute neutrophil count (ANC) ≥ 1500 / mm3;
• platelet count ≥ 100000 / mm3;
• total bilirubin ≤ 1.5 times the upper limit of normal value (ULN);
• glutamic pyruvic transaminase and glutamic oxalic transaminase ≤ 2.5 times ULN;
• creatinine ≤ 1.5 times ULN;
• Patients or family members who can understand the study protocol and are willing to participate in the study shall provide written informed consent.

Exclusion criteria

• Receive chemotherapy, radiotherapy or immunotherapy before operation
• History of malignant tumor in the past 5 years (except fully cured cervical carcinoma in situ or basal cell carcinoma or squamous epithelial cell skin cancer)
• Pregnant women
• Serious mental illness
• Those with poor physical condition and difficult to complete chemotherapy
• Patients or family members cannot understand the conditions and objectives of this study