Application and Exploration of Personalized ctDNA-MRD Detection Technology in Predicting the Efficacy of Neoadjuvant Therapy for Rectal Cancer

Inclusion Criteria: * 1: Signed a written informed consent form and voluntarily participated in this study * 2: Aged 18-75 years, regardless of sex * 3: Histopathologically confirmed rectal adenocarcinoma * 4: Clinical stage II-III as assessed by MRI (according to the AJCC 8th edition) * 5: Distance from the lower tumor margin to the anal verge ≤10 cm * 6: Surgically resectable * 7: Able to swallow tablets normally * 8: ECOG PS 0-1 * 9: No prior antitumor therapy for rectal cancer, including radiotherapy, chemotherapy, or surgery * 10: Scheduled to undergo surgical treatment after completion of neoadjuvant therapy * 11: No surgical contraindications * 12: Normal function of major organs, including: complete blood count, blood biochemistry, and coagulation function Exclusion Criteria: * 1: History of allergy to monoclonal antibodies, any component of tislelizumab, or capecitabine * 2: Prior or ongoing receipt of any tumor-directed surgery, radiotherapy, chemotherapy, targeted therapy, immunotherapy, etc * 3: Presence of any active autoimmune disease or history of autoimmune disease * 4: History of immunodeficiency, including a positive HIV test result, other acquired or congenital immunodeficiency disorders, or history of organ transplantation or allogeneic bone marrow transplantation * 5: Poorly controlled cardiac clinical symptoms or diseases, including but not limited to: heart failure of NYHA class II or above, unstable angina, myocardial infarction within the past year…