By Miriam Komaromy, MD

Reviewed by Peggy Conrad, MS, CGC and Jonathan Terdiman, MD
Last updated August 4, 2000

Familial Adenomatous Polyposis (FAP) is a medical syndrome that makes it extremely likely that you will eventually be diagnosed with multiple colon polyps and, without preventive colon surgery, colon cancer. If there is a possibility that you may have inherited FAP, you need to follow some rigorous screening and prevention guidelines to manage your long-term health.

Why Take Extra Precautions?

Why FAP Patients Need to Follow Intensive Screening and Prevention Guidelines Nearly 100 percent chance of developing colon cancer. Tendency to develop cancer at a very young age. Removal of individual polyps does not effectively prevent cancer.

Virtually all colon cancer develops from polyps, or mushroom-shaped growths, on the inside wall of the colon. In FAP patients, such polyps characteristically develop at an early age and at an astonishing rate. It's not unusual for a person with FAP syndrome to develop hundreds or even thousands of these polyps.

For this reason, the American Gastroenterological Association has developed specific screening and prevention guidelines.

How Your Risk Guides Screening and Prevention

Depending on the certainty of your personal FAP risk, you may have slightly different screening and prevention guidelines. There are four basic scenarios for people with FAP in their family:

• You Know You Have an FAP-Causing Mutation. You need to be follow rigorous screening and prevention guidelines.
• No Mutation Has Been Identified as the Cause of FAP in Your Family. You should assume you are at high risk for FAP and follow the same rigorous colon screening procedures as FAP mutation carriers. (This is true whether no specific mutation is known to be in your family because genetic testing has not been done, or because testing did not give conclusive results.)
• No Mutation Has Been Identified as the Cause of FAP in Your Family AND You Are Polyp-Free at Age 40 (or older). The chances that you actually have FAP are greatly reduced. This means you may now be able to follow slightly less rigorous screening and prevention guidelines.
• You Know You Do NOT Have an FAP-Causing Mutation. If genetic testing has definitively shown that you do not carry the FAP-causing mutation known to run in your family, you can revert to the much less stringent colon cancer screening guidelines recommended for the general population.

Rigorous Screening and Prevention Guidelines

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More on Genetic Testing for FAP

Genetic testing can only yield a truly negative result for FAP when a genetic mutation has already been identified for a particular family.

It's important to emphasize that genetic testing can only yield a truly negative result for FAP when a genetic mutation has already been identified for a particular family.

The most appropriate way to monitor for polyps is through sigmoidoscopy, a procedure that allows your doctor to visually locate and remove polyps by placing a tube with a light and viewing camera at one end into your anus and guiding it along the lower third of your colon. People at high risk of FAP should begin screening at age 10.

In families who have a rare version of the syndrome called attenuated FAP, a similar but more thorough procedure called a colonoscopy is recommended because of the particular ways that version of FAP attacks the colon.

Intermediate Screening and Prevention Guidelines

If you come from a family with a history of FAP but in which no genetic mutation has been identified, and regular screening fails to find polyps as you grow older, the chances diminish that you have inherited the defective gene that causes FAP.

For this reason, the National Comprehensive Cancer Network (NCCN) has set forth age-dependant screening recommendations for people who are statistically at less risk as they grow older and no polyps have been found:

• Anyone at risk for FAP but who has not had their diagnosis confirmed by genetic testing should be screened yearly, by sigmoidoscopy, from age 10 to 24.
• At that point, screening should occur every two years until age 34.
• Then every three years until age 44
• And every three to five years thereafter

What´s Next if Polyps Are Found?

Upper Bowel Cancer Screening

Medications That May Prevent Polyp Formation

A number of studies suggest that certain drugs may decrease the number or size of colon polyps in FAP patients (although the jury is still out as to whether they also reduce the risk that a given individual will eventually be diagnosed with colon cancer). These drugs include sulindac, aspirin, and Celebrex, among others.

The only currently accepted treatment for FAP is surgery.

In general, however, genetic specialists are extremely cautious when talking about using these drugs, primarily because they don't want to raise false hopes — the only currently accepted treatment for FAP is surgery.

The good news is that using drugs like sulindac and Celebrex may help to slow polyp growth so that younger FAP patients who haven't yet had their colons removed surgically can perhaps gain some time to make that difficult decision. These drugs can also be used for people who have had their colons removed but decided to leave their rectums intact since they help prevent polyps from growing in the remaining rectum. Such drugs may even prove to help prevent the growth of polyps in the stomach or small intestine.

Because some of these drugs have also been known to cause gastrointestinal bleeding, doctors don't always recommend them for FAP patients. Celebrex is approved by the US Food and Drug Administration for use by FAP patients for reduction in the number of adenomatous colorectal polyps in FAP, as an adjunct to endoscopy and surgery.

If you are considering taking these drugs, you should only do so after consulting with your physician. It is important to remember that these drugs do not cure polyposis. People who take these medications will still need to undergo the screening and surveillance procedures recommended above.

References

Winawer, S. et al. (1997). Colorectal cancer screening: clinical guidelines and rationale. Gastroeneterology 112: 594-642.

Levin, B. et al. (1999). NCCN colorectal cancer screening practice guidelines. Oncology 13(5A): 152-179.

Hawk, E. et al. (1999). Chemoprevention in hereditary colorectal cancer syndromes. Cancer 86: 2551-63.

Wallace, M. and Phillips, R.(1998). Upper gastrointestinal disease in patients with familial adenomatous polyposis. Br J Surg 85(6): 742-50.

Henney, J. (2000). From the FDA: celecoxib indicated for FAP. JAMA 283(9): 1131