Colorectal Cancer Clinical Trials

• Before conducting procedures related to the research protocol but not part of routine care, written informed consent, voluntarily signed and dated by the subject, must be obtained in accordance with regulations and institutional guidelines.

• Age 18-75 years.

• Histologically or cytologically confirmed pMMR/MSS rectal adenocarcinoma; all other histological types are excluded.

• Distance from the lower margin of the rectal tumor to the anal verge ≤10 cm.

• Clinical staging with high-risk factors, including cT3Nx, EMVI(+), or cT4, ±MRF(+), ±EMVI(+).

• No evidence of distant metastasis before treatment.

• No prior anti-cancer treatment (radiotherapy, chemotherapy, targeted therapy, or immunotherapy).

• ECOG performance status of 0-1.

• Peripheral blood counts and liver and kidney function within the following allowable ranges (tested within 15 days before the start of treatment):

∙ White blood cells (WBC) ≥3.0×10\^9/L or absolute neutrophil count (ANC) ≥1.5×10\^9/L;

‣ Hemoglobin (HGB) ≥80 g/L;

‣ Platelets (PLT) ≥100×10\^9/L;

‣ Liver transaminases (AST/ALT) \<3.0 times the upper limit of the normal range;

‣ Total bilirubin (TBIL) \<1.5 times the upper limit of the normal range;

‣ Creatinine (CREAT) \<1.5 times the upper limit of the normal range.

⁃ No history of other malignancies; not pregnant or breastfeeding, and effective contraception must be used during the study period and for 6 months after the last dose.