CEA CAR-T Therapy After Cytoreduction in Colorectal Cancer Patients With Peritoneal Metastases

This study tests CEA-targeted CAR-T cell therapy (immune cells engineered to target the CEA protein found on colorectal cancer cells) given after cytoreductive surgery (surgery to remove as much cancer as possible) in people with colorectal cancer that has spread to the lining of the abdomen (peritoneal metastases). **You may be eligible if...** - You are 18 to 75 years old with confirmed colorectal cancer that has spread to the peritoneum - Standard treatments (oxaliplatin, irinotecan, fluorouracil, etc.) have failed or you have no effective treatment options - You have already undergone or are planned for cytoreductive surgery for your peritoneal metastases - Your tumor cells express the CEA protein **You may NOT be eligible if...** - Your cancer has spread to other distant organs beyond the peritoneum (e.g., liver, lungs) without control - You have serious organ dysfunction - You have active infections or autoimmune conditions - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.