Attenuated familial adenomatous polyposis

In general, colectomy (removal of all or part of the colon) may be considered in individuals with attenuated familial adenomatous polyposis (AFAP) when the number of polyps is too many to remove during colonoscopy. Management guidelines for AFAP also suggest that colectomy may be appropriate when 21 or more polyps are identified during one colonoscopy, if any polyp is greater than one centimeter in size, or if any polyp is found to contain cells that appear cancerous. Colectomy may also be considered if an individual with AFAP cannot or will not undergo regular screening.

The decision to have a colectomy is a very personal one and should be discussed with a physician who is familiar with AFAP; any decision should be based on physical findings, genetic testing results, and personal considerations.

There is limited literature available that is specific to attenuated familial adenomatous polyposis (AFAP). Therefore, many experts suggest that people with AFAP follow the same screening guidelines as those with classic familial adenomatous polyposis (FAP), which may include:

• If total colectomy with ileo-anal pull-through was performed: routine screening of the ileal pouch every two years
• If subtotal colectomy (removal of part of the colon) was performed: screening of the remaining rectum every six to 12 months, depending on the number of polyps that develop. Cancer may still occur in the remaining rectum, but the risk is much lower.
• Annual physical examination with palpation of the thyroid with consideration of follow-up ultrasound examination and fine-needle aspiration if thyroid nodules are present

Extra colonic manifestations of FAP generally require affected people to follow a lifelong screening program for the diagnosis and treatment of desmoid tumors and benign and malignant tumors of the duodenum (a section of the small intestine), stomach, bones, skin, and other tissues.

Additional and more detailed information about follow-up recommendations for individuals with FAP or AFAP, including post-surgery recommendations is available at the following links:

• GeneReviews - APC-Associated Polyposis Conditions
• American Society for Colon and Rectal Surgeons - Familial Adenomatous Polyposis (FAP)
• Elizabeth Half, Dani Bercovich, and Paul Rozen. Familial adenomatous polyposis. Orphanet J Rare Dis. 2009; 4: 22.

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.