Research on Colorectal Cancer Recurrence Monitoring and Individualized Treatment Based on MRD

Inclusion criteria

• Voluntary participation in the study and provision of written informed consent.
• Age ≥18 years at the time of signing informed consent.
• Histologically confirmed colorectal adenocarcinoma with mismatch repair deficiency (dMMR) or microsatellite instability-high (MSI-H) status.
• Clinically confirmed stage IV disease.
• No prior immunotherapy for the current colorectal cancer.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-1.
• Availability of adequate pretreatment tumor tissue and peripheral blood samples for whole-exome sequencing (WES) and personalized circulating tumor DNA (ctDNA)/MRD analysis.
• Life expectancy >12 months.
• Willing and able to comply with the study procedures and scheduled follow-up.

Exclusion criteria

• Presence of another malignancy.
• Prior immunotherapy for the current stage IV colorectal cancer.
• Organ transplantation within 3 months before enrollment.
• History of blood transfusion within 3 months before enrollment.
• Active, known, or suspected autoimmune disease, or evidence of active or chronic infection with hepatitis B virus, hepatitis C virus, or human immunodeficiency virus (HIV).
• Pregnancy or breastfeeding.
• Presence of a serious concurrent disease that, in the investigator's judgment, may substantially affect life expectancy or study participation.
• Failure to provide written informed consent.
• Any other condition that, in the investigator's judgment, makes the participant unsuitable for enrollment.