Attenuated familial adenomatous polyposis (AFAP) is an inherited condition that increases the chance to develop cancer of the large intestine (colon) and rectum. It is a milder form of classic familial adenomatous polyposis (FAP) and is characterized by fewer colon polyps (an average of 30) and a delay in the development of colon cancer (average age 50 to 55 years). Other signs and symptoms may include benign or malignant tumors of the duodenum (a section of the small intestine) and, in rare cases, other symptoms of FAP. AFAP is caused by mutations in the APC gene and is inherited in an autosomal dominant manner. AFAP is generally managed with regular screening to detect if and when polyps develop.

Attenuated familial adenomatous polyposis (AFAP) is generally managed with regular screening to detect if and when polyps develop. Screening by colonoscopy has been recommended for affected people starting at age 20 to 25 years. People with polyps may undergo polypectomy (removal of polyps) followed by continued screenings every one to three years, depending on the number of polyps. A prophylactic colectomy (removal of all or part of the colon) may be considered in people with too many adenomas to remove or those who cannot undergo screening. About one third of people with AFAP have few enough colon polyps that screening with periodic polypectomy is sufficient.

Because individuals with AFAP can also develop duodenal adenomas and other cancers, upper endoscopy is typically recommended starting at age 20 to 30 years and then every one to three years, depending on the number of polyps. There is currently no consensus on screening for tumors that occur outside of the colon, so it has been suggested that affected individuals are managed as if they have classic FAP.

A number of drugs such as celecoxib and sulindac reportedly have been successful at reducing the number and the size of polyps in affected people, but these drugs generally help to prevent further complications and are not considered adequate treatment.

Additional and more detailed information about the treatment and management of FAP, including AFAP, is available on eMedicine's Web site and can be viewed by clicking here.