Duodenal Polyposis Classification in FAP

This study is looking at how polyps in the small intestine (duodenum) progress over time in people with familial adenomatous polyposis (FAP) — a genetic condition that causes many polyps to grow throughout the digestive tract, with a high risk of becoming cancerous. Researchers want to improve how these polyps are classified and monitored. **You may be eligible if...** - You have a confirmed genetic diagnosis of FAP - You have had at least two upper gastrointestinal endoscopy procedures - All the relevant measurements from your scope procedures are fully documented **You may NOT be eligible if...** - Your polyp tissue samples were not fully analyzed - Follow-up data from your procedures are missing - You had surgery on your duodenum (small intestine) before the study's starting point Talk to your doctor to see if this trial is right for you.