Familial Adenomatous Polyposis (FAP) FAP is a syndrome characterized by a large number of benign polyps in the colon and rectum. Without treatment, a person with FAP has a nearly 100 percent risk of colorectal cancer. Other Colorectal Cancer Syndromes Several rare syndromes raise the risk for colorectal cancer. These disorders include Turcot syndrome, Peutz-Jeghers syndrome, juvenile polyposis coli, and MYH-associated polyposis. Ovarian Cancer as Part of Lynch Syndrome A woman with this type of hereditary colon cancer is at increased risk for ovarian cancer.