A Prospective Single-Arm Study of Short-Course Radiotherapy Followed by PD-1 Monoclonal Antibody, Bevacizumab, Oxaliplatin, and Trifluridine/Tipiracil for Total Neoadjuvant Therapy in MSS Locally Advanced Low Rectal Cancer. This is a Non-Randomized, Single Group Assignment, Open Label, Phase: Phase II study. The Primary Objective is to assess the organ preservation rate (clinical complete response, cCR) after total neoadjuvant therapy. Secondary Objectives are Tumor regression grade (TRG), 3-year overall survival (OS) and disease-free survival (DFS), and Safety and quality of life (QoL). In this study, the investigators will perform the multi-dimensional omics study to explore the tumors microenvironments, explore the characteristics of the treatment benefit population, and try to construct an efficacy prediction model to screen the treatment benefit population early and implement precise treatment.
Patients who are willing to receive neoadjuvant therapy.
≧18 years old.
Diagnosed by digital rectal examination, colonoscopy, and high-resolution MRI of the pelvis, the tumor is less than or equal to 5 cm from the anus.
Histologically diagnosed as rectal adenocarcinoma.
History of other malignant diseases in the past 5 years.
Patients with metastases from other sites (stage IV patients).
Patients withT4b or positive lateral lymph nodes by pelvic contrast-enhanced CT and pelvic high-resolution MRI.
Patients with intestinal obstruction, intestinal perforation, intestinal bleeding, etc. requiring emergency surgery.