MRD-Guided Surveillance in Locally Advanced Mid-Low Rectal Cancer (SURVEILLANCE-III)

Inclusion Criteria:

1） Age 18-80 years old, male or female; 2) histologically confirmed diagnosis of rectal adenocarcinoma (i.e., adenoepithelial carcinoma, including adenocarcinoma, mucinous carcinoma, imprinted cell carcinoma, and undifferentiated carcinoma; excluding adenosquamous carcinoma); 3) Preoperative clinical stage cT3 /N+, M0, the lower edge of the tumor is ≤10cm from the anal verge, and no surgical resection is performed; (4) Not receiving chemotherapy, radiotherapy, targeted therapy or other anti-tumor therapy; 5) Radical surgery is available; 6) ECOG score 0-1; 7) Subjects voluntarily enrolled in this study and signed the informed consent, good compliance, follow the planned schedule and actively cooperate with the return to the hospital for regular clinical follow-up and necessary treatment.

Exclusion Criteria:

1. previous other malignant tumors (including non-adenocarcinoma colorectal cancer);
2. Previously received other anti-tumor therapy;
3. Pregnant and lactating women; (4) Patients with other medical conditions that, in the judgment of the investigator, may interfere with follow-up and short-term survival;

5\) Subjects have other factors that may lead to forced termination of this study, such as other serious illnesses (including mental illness, infectious diseases, fever ≥38℃, etc.) that require combined treatment, serious laboratory test abnormalities, accompanied by family or social factors that will affect the safety of the subjects, or the collection of data and samples.