Familial adenomatous polyposis (called “FAP” here) is a disease that causes abnormal growths within the bowel (also called the colon), rectum, and other areas. Gastroenterologists call these growths “polyps.” they’re not cancer, but can become cancer.
Most people with FAP have hundreds or thousands of polyps. This suggests they have a way higher risk of colon cancer than others. Without treatment, the majority of people who have FAP get colon cancer by age 45. Some people have a milder variety of FAP that causes fewer polyps. People with FAP also can develop cancer of the stomach, small intestine, thyroid, pancreas, or brain. FAP is caused by an abnormal gene that runs in families. Those who have FAP usually start showing signs of it in their teens or 20s. But some people get it in childhood.