Collecting Blood and Stool Samples to Detect Colorectal Cancer or Advanced Neoplasia in Lynch Syndrome Patients

This study is collecting blood and stool samples from people with Lynch syndrome — a hereditary condition that greatly increases the risk of colorectal and other cancers — to develop better blood or stool tests for early detection of colorectal cancer. **You may be eligible if...** - You are 18 or older - You have been diagnosed with Lynch syndrome (confirmed gene mutation in MLH1, MSH2, MSH6, PMS2, or EPCAM) or are suspected to have it - Or you were diagnosed with colorectal cancer before age 50 - You have a colonoscopy or sigmoidoscopy scheduled within 90 days of sample collection **You may NOT be eligible if...** - You have been diagnosed with any cancer (stages I–IV) in the last 5 years (excluding common skin cancers) - You do not have a scheduled colonoscopy Talk to your doctor to see if this trial is right for you.