Clinical Research Directory

Inclusion Criteria: 1. Pathologically confirmed rectal adenocarcinoma; 2. Mid-low rectal cancer, with the lower edge of the tumor located within 12 cm from the anal verge; 3. Magnetic resonance imaging (MRI) suggests locally advanced rectal cancer (T3 or T4 and M0), accompanied by at least one of the following risk factors: cT4, N2, lymphovascular invasion, involvement of the mesorectal fascia, or enlarged lateral lymph nodes (short-axis diameter \> 8 mm); patients with potentially resectable disease; 4. Polymerase chain reaction (PCR) testing indicates microsatellite stability (MSS) type; 5. No prior antitumor therapy, such as chemotherapy, radiotherapy, immunotherapy, or targeted therapy; 6. Age between 18 and 75 years; 7. ECOG Performance Status (PS) score of 0-1; 8. Laboratory test results: WBC ≥ 3.5 × 10\^9/L, Hb ≥ 100 g/L, PLT ≥ 100 × 10\^9/L; normal liver and kidney function; 9. Absence of severe comorbidities, and ability to tolerate surgical treatment; 10. The patient or their immediate family member voluntarily agrees to participate in this study and provides written informed consent. Exclusion Criteria: 1. Recurrent rectal cancer; 2. Synchronous colorectal cancer; 3. Pregnant or lactating patients; 4. History of other malignant tumors; 5. Previous antitumor therapy, including chemotherapy or radiotherapy; 6. Dysfunction of vital organs such as cardiac or pulmonary insufficiency; 7. History of autoimmune diseases or immunodeficiency disorders; 8. Use of immunosuppressive drugs within the past year; 9. Distant metastasis to organs such as the abdominal cavity, pelvis, liver, or lungs; 10. Active bleeding; 11. Tumor involvement of adjacent structures such as the prostate or sacral organs, making the tumor unresectable; 12. Allergy to chemotherapeutic agents, immune checkpoint inhibitors, or cetuximab; 13. Psychiatric disorders or lack of capacity for civil conduct, unable to provide informed consent.