Familial Adenomatous Polyposis (FAP) | Diagnosis & Treatments


How is familial adenomatous polyposis diagnosed?

Children are tested for familial adenomatous polyposis (FAP) by performing a colonoscopy. A doctor uses a long, flexible tube with a light and camera on the end to look inside the rectum and up into the large intestine. An upper GI endoscopy is often done at the same time. An upper GI endoscopy also uses a long, flexible tube but looks down into the esophagus (food tube), stomach, and small intestine.

Another way to check for FAP is by genetic testing. Detection of the gene mutation is very accurate, detecting approximately 95 percent of cases and with 98 percent accuracy. Other screening studies may include radiology imaging.

When should my child be tested for FAP?

Children should be screened for FAP if there is a family history of FAP or colon cancer at a young age, or if they have any unusual growths or lesions. An initial screening should be done:

  • by 8 to 10 years of age for a child with a high-risk family history
  • by 10 to 12 years of age for an average-risk patient
  • at the time of first symptoms

Average and high-risk patients are determined based on family history or known high-risk gene mutations.

What are the treatment options for FAP?

The most important treatment for FAP is the early removal of the entire colon (prophylactic colectomy) to prevent the development of cancer. The timing of surgery is based on the patient’s age or other high-risk factors, including family history, polyp number, and pre-malignant changes in the polyps.

There is no cure for FAP. Treatment is directed to reduce complications, such as cancer, abdominal pain, bowel obstruction, and GI bleeding.