A rare, inherited disorder in which multiple polyps (abnormal growths) form on the inner walls of the colon and rectum. People with AFAP usually develop fewer than 100 polyps. Benign (not cancer) tumors may also occur in the stomach, small intestine, bone, skin, and soft tissue. People with AFAP have a very high risk of developing colorectal cancer and may also be at risk of developing cancers of the stomach, small intestine, liver, and breast. AFAP is caused by mutations (changes) in the APC gene that are inherited in an autosomal dominant manner. It is a type of hereditary cancer syndrome. Also called attenuated familial adenomatous polyposis.