Familial Adenomatous Polyposis

Familial adenomatous polyposis is a genetic disorder that predisposes you to develop precancerous colon polyps called adenomas. Colon polyps are abnormal growths in the lining of your colon or rectum. They aren’t cancer, but certain types, like adenomas, can change into colorectal cancer.

Many people get a few colon polyps at random as they get older. But if you have a hereditary polyposis syndrome like FAP, you’ll develop many colon polyps — typically over a hundred — starting from a young age. This significantly raises your lifetime risk that one of them will become cancerous.

To manage this risk, healthcare providers usually recommend complete removal of the colon (total colectomy) and sometimes the rectum, too (proctocolectomy). Polyps in FAP appear too frequently to manage them one by one. Without surgery, most people with FAP will develop cancer by their middle-age years.

People with FAP may also develop polyps in other organs, and other abnormal growths in places like their skin, soft tissues, teeth and bones. Even after colectomy surgery, they’ll need to continue to have regular screenings for other tumors, and possibly additional surgeries to manage those tumors.

What is the estimated cancer risk with familial adenomatous polyposis?

Without treatment, the risk of developing colorectal cancer with familial adenomatous polyposis is close to 100%. It also develops relatively earlier and faster with FAP than in those without. Children in families known to be affected by the syndrome begin yearly colonoscopy screenings at the age of 10.

Besides colorectal cancer, people with familial adenomatous polyposis also have an increased risk of developing other cancers, including:

Duodenal cancer (8%).
Papillary thyroid cancer (2%).
Pancreatic cancer (2%).
Hepatoblastoma (1.5%).
Stomach cancer (1%).
Brain and spinal tumors (less than 1%).

Are there different types of FAP?

Familial adenomatous polyposis has a classic form and some less common forms that are considered subtypes.

“Classic” FAP is characterized by more than 100 adenomatous polyps in your colon.
“Attenuated” FAP (AFAP) is a less severe subtype in which you have somewhere between 20 and 100 colon polyps.
Gardner syndrome, like classic FAP, typically involves over a hundred colon polyps, as well as other types of tumors in other body parts.
Turcot syndrome involves multiple colon polyps, as well as one cancerous brain tumor.

How common is familial adenomatous polyposis?

Familial adenomatous polyposis is rare, estimated to affect about 1 in 8,000 people. It accounts for only about 0.5% of all colorectal cancer cases. Variants like AFAP, Gardner syndrome and Turcot syndrome are rarer. They represent between 5% and 10% of all familial adenomatous polyposis cases.

What’s the difference between familial adenomatous polyposis (FAP) vs. Lynch syndrome?

Lynch syndrome is a different hereditary syndrome that can raise your risk of developing colorectal cancer and other cancers. Lynch syndrome is also sometimes called hereditary nonpolyposis colorectal cancer syndrome (HNPCC). As the name suggests, it doesn’t necessarily cause a lot of colon polyps.

People with Lynch syndrome may develop colorectal cancer with only one or a few colon polyps. Polyps and cancer also tend to develop a little later than in classic FAP, and the lifetime risk is a bit lower. Different gene mutations lead to the differences between Lynch Syndrome and FAP.

Symptoms

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Complications

Blood clots are a dangerous complication of atrial fibrillation (AFib). Blood clots can lead to stroke.

The risk of stroke from AFib increases as you grow older. Other health conditions also may increase the risk of a stroke due to AFib. These conditions include:

High blood pressure.
Diabetes.
Heart failure.
Some types of heart valve disease.

Blood thinners are commonly prescribed to prevent blood clots and strokes in people with atrial fibrillation.

Prevention

Healthy lifestyle choices can reduce the risk of heart disease and may prevent atrial fibrillation (AFib). Here are some basic heart-healthy tips:

Control high blood pressure, high cholesterol and diabetes.
Don't smoke or use tobacco.
Eat a diet that's low in salt and saturated fat.
Exercise at least 30 minutes a day on most days of the week unless your health care team says not to.
Get good sleep. Adults should aim for 7 to 9 hours daily.
Maintain a healthy weight.
Reduce and manage stress.

By Mayo Clinic Staff

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