FAP syndrome

Familial adenomatous polyposis (FAP) is an inherited disorder sometimes found in people with colorectal cancer. 

People with FAP may develop noncancerous (benign) colon polyps as early as their teenage years.

The facts

  • Familial adenomatous polyposis (FAP) is an inherited disorder sometimes found in people with colorectal cancer.
  • Approximately two percent of all colon cancer could be caused by a hereditary adenomatous polyposis condition.
  • People with the classic type of FAP may develop noncancerous (benign) colon polyps as early as their teenage years
  • Screening usually begins at eight to ten years old.
  • The type of polyp most often seen in FAP syndrome, called an adenoma, is precancerous.
  • The average age at which an individual with FAP develops colorectal cancer is 39 years old.
  • Some people have a variation of the disorder, called attenuated familial adenomatous polyposis (AFAP), with fewer polyps.
  • The average age of colon cancer onset for those with AFAP is 55 years.
  • People with FAP can also develop noncancerous growths called desmoid tumors.

 

woman in lab in white coat

Other tumors in the body

In both classic FAP and AFAP, benign and cancerous tumors are sometimes found in other places in the body, including the small intestine, stomach, bones, skin, and other tissues. People who have colon polyps outside the colon are sometimes described as having Gardner syndrome.

Causes, risks, prediction, and screening

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