Early Onset Colorectal Cancer Detection

This study aims to develop and improve blood-based tests (liquid biopsy) to detect colorectal cancer that starts at a young age — specifically in people diagnosed before age 50, which is called early-onset colorectal cancer (EOCRC). **You may be eligible if...** - You were diagnosed with colorectal cancer (any stage) before the age of 50 - You have undergone standard diagnostic procedures and had blood drawn before any curative treatment - OR you are cancer-free and had a normal colonoscopy (as a healthy comparison group) **You may NOT be eligible if...** - You have a hereditary colorectal cancer syndrome identified by genetic testing (such as Lynch syndrome or familial adenomatous polyposis) - You have inflammatory bowel disease (Crohn's disease or ulcerative colitis) - You have not provided written informed consent Talk to your doctor to see if this trial is right for you.