Can people under 45 get colorectal cancer?
In general, it is very uncommon for younger people to get colorectal cancer if there is no family history and if the person is under 30.
However, there are two well-recognized hereditary syndromes in which cancer can develop in young people. The first is Familial Adenomatous Polyposis (FAP). This is a disease in which affected people develop hundreds to thousands of precancerous polyps in the colon. Unless the colon is removed, 100% of these patients will get colorectal cancer, usually by their late 30s.