Familial adenomatous polyposis (FAP) is a rare, inherited condition that causes colorectal cancer. FAP results in the development of hundreds of polyps inside the large intestine.
FAP is caused by a genetic defect. Polyps usually begin developing during during the teenage years, and 95% of people with FAP will have polyps by age 35. The average person with FAP will have colorectal cancer found by the age of 39 years.
The primary risk factor for FAP is having family members with this condition. However, this condition can occur in people without a family history of the condition. This is because the genetic defect can caused by a new mutation in the affected person.
In the early stages, there may be no symptoms. When symptoms do occur, they may include:
Your doctor will ask about your symptoms and medical history. A physical exam will be done. To confirm a diagnosis, your doctor will do some tests. These may include:
An endoscopy is a thin, lighted, telescope-like tube with a camera that is used to look for polyps inside the intestines. Endoscopy for FAP may include:
FAP is treated with surgery. Since FAP causes so many polyps, they cannot be removed individually. Therefore, the goal of surgery is to remove the portion of the intestine that contains the cancerous or precancerous polyps. The surgical procedure used depends on the length of intestine involved.
The three main surgical treatments are:
Duodenal polyps in the small intestine are managed with endoscopy. An endocope is used to find the polyps. Once found, the surgeon inserts small tools through a tube in the endoscope and removes them. In some cases, surgery to remove the duodenum may be done.
Medications are used shrink polyps and to prevent new ones from forming. Medications include:
The remaining intestine will need to be inspected by endoscopy as often as every 6 months for the rest of your life. Because the risk of developing other polyps that could grow to become cancer is so high, it is crucial for your doctor to keep a very close watch. If more polyps arise, further surgery may be required.
Canadian Cancer Society
Colorectal Cancer Association of Canada
FAP. Cleveland Clinic website. Available at: http://my.clevelandclinic.org/disorders/inherited_colon_cancer/dd_fap.aspx. Accessed May 24 ,2013.
Familial adenomatous polyposis. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated June 25, 2012. Accessed May 24, 2013.
Familial adenomatous polyposis . Genetics Home Reference website. Available at: http://ghr.nlm.nih.gov/condition/familial-adenomatous-polyposis. Updated April 2008. Accessed May 24, 2013.
Jasperson KW, Burt RW. APC -associated polyposis conditions. GeneReviews. Available at: http://www.ncbi.nlm.nih.gov/books/NBK1345. Updated October 27, 2011. Accessed May 24 ,2013.
Last reviewed May 2014 by Mohei Abouzied, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.