A Single-Center, Single-Arm Study of Neoadjuvant Short-Course Radiotherapy With IL-2 Followed by Sequential Immunotherapy With CAPOX Combined With PD-1 Antibody and IL-2 for Locally Advanced Rectal Cancer

This study is testing a new treatment approach for locally advanced rectal cancer that combines short-course radiation therapy with an immune-boosting protein (IL-2) followed by chemotherapy and an immunotherapy drug (PD-1 antibody), to try to eliminate the cancer without always needing surgery. **You may be eligible if...** - You are between 18 and 70 years old - You have been diagnosed with rectal cancer (adenocarcinoma) confirmed by tissue sample - You are in good physical health (ECOG 0 or 1) - Your blood counts, liver, and kidney function are within acceptable ranges **You may NOT be eligible if...** - Your cancer has spread to distant organs (metastatic) - You have serious heart, autoimmune, or immune system conditions - You have previously received chemotherapy or radiation for rectal cancer Talk to your doctor to see if this trial is right for you.