Familial Adenomatous Polyposis

Overview

Familial adenomatous polyposis (FAP) is a rare, inherited genetic condition caused by a defect in the adenomatous polyposis coli (APC) gene. The defect results in the formation of extra tissue, known as polyps, in the large intestine (colon) and rectum. FAP increases the risk of colon and rectal cancer, with polyps becoming cancerous in the 40s if left untreated. Most people with FAP eventually require surgery to remove the colon to prevent cancer. A milder form of the condition, attenuated familial adenomatous polyposis (AFAP), involves fewer colon polyps and a later onset of cancer.

Understanding the disease

Symptoms

The main symptom of familial adenomatous polyposis (FAP) is the presence of hundreds or even thousands of polyps growing in the colon and rectum, usually starting by mid-teens. These polyps are highly likely to develop into colon cancer or rectal cancer by the time the individual reaches their 40s. Other complications associated with FAP include duodenal polyps, periampullary polyps, gastric fundic polyps, desmoids, and other cancers in rare cases.

Risk Factors

The risk factors for developing familial adenomatous polyposis (FAP) are:

1. Inheriting the abnormal gene from a parent: Most people inherit the gene from a parent, but for 25 to 30 percent of people, the genetic mutation occurs spontaneously.
2. Having a family history: Your risk of FAP is higher if you have a parent, child, brother, or sister with the condition.

Development

Familial adenomatous polyposis (FAP) is caused by a defect in the adenomatous polyposis coli (APC) gene. This inherited genetic mutation leads to the formation of extra tissue (polyps) in the large intestine (colon) and rectum, as well as other parts of the gastrointestinal tract, such as the upper part of the small intestine (duodenum). In people with FAP, the polyps are nearly 100% certain to develop into colon or rectal cancer by the time they reach their 40s if left untreated. The risk of developing FAP is higher if a parent, child, brother, or sister has the condition. There are different types of familial adenomatous polyposis, including:

1. Attenuated familial adenomatous polyposis (AFAP): People with AFAP usually have fewer colon polyps (an average of 30) and develop cancer later in life compared to those with classic FAP.
2. Gardner syndrome: A variant of FAP, Gardner syndrome causes polyps to develop throughout the colon and small intestine, as well as noncancerous tumors in other parts of the body, such as the skin, bones, and abdomen. It is essential to monitor and manage polyps through regular screenings and surgeries to prevent the development of cancerous tumors in people with FAP and its variants. Genetic testing can help determine the risk of developing FAP and guide appropriate preventive measures.

Assessment and Diagnosis

Triage

You should see a doctor if you suspect familial adenomatous polyposis if you experience symptoms such as abdominal pain, blood in your stool, or a change in your bowel habits that lasts for more than a week. It's important to seek medical attention for these symptoms, as they could indicate the presence of polyps or other complications associated with the condition.

Diagnosis

To diagnose familial adenomatous polyposis (FAP), doctors typically follow a few different approaches. These include:

1. Genetic testing: A simple blood test can determine if a person carries the abnormal gene that causes FAP. Genetic testing may also detect whether a person is at risk of complications of FAP.
2. Physical examination: A doctor may perform a pelvic exam to feel for any abnormalities in the reproductive organs, as well as a rectal exam to examine the rectum and colon for any abnormalities.
3. Imaging tests: Imaging tests such as CT scans or MRI may be used to evaluate the extent of the condition and detect any complications.
4. Biopsy: In some cases, a biopsy may be performed to remove a small tissue sample for further study. This can help confirm the diagnosis of FAP. It is important to note that other conditions can cause similar symptoms to FAP, so ruling out these other possibilities is crucial before making a diagnosis.

Management and Treatment

Complications

Potential complications of familial adenomatous polyposis (FAP) include:

1. Colon cancer: The polyps in the colon and rectum are nearly 100% certain to develop into colon cancer or rectal cancer by the time the affected individual reaches their 40s.
2. Duodenal polyps: Polyps may also form in the upper part of the small intestine (duodenum), which can become cancerous if left untreated. However, regular monitoring and polyp removal can help prevent cancer development.
3. Periampullary polyps: These polyps grow where the bile and pancreas ducts enter the duodenum (ampulla). Like duodenal polyps, they may become cancerous but can often be detected and removed before cancer develops.
4. Gastric fundic polyps: These polyps grow in the lining of the stomach.
5. Desmoids: Noncancerous masses that can arise anywhere in the body, often in the stomach area, and can cause problems if they grow into nerves, blood vessels, or exert pressure on other organs.
6. Other cancers: FAP may rarely cause cancer to develop in the thyroid gland, central nervous system, adrenal glands, liver, or other organs.
7. Complications of surgery: The removal of the large intestine (colectomy) is often necessary to prevent cancer in individuals with FAP. This surgery may result in complications such as infection, bleeding, or difficulties with bowel function. It is important to note that some of these complications are more common in other conditions similar to FAP, such as MUTYH-associated polyposis (MAP) and serrated polyposis syndrome. Genetic testing and proper diagnosis can help determine the specific risks and potential complications associated with these conditions.

Home Remedies

It is important to consult with a healthcare professional for proper diagnosis, treatment, and management of familial adenomatous polyposis. They can provide guidance on the best course of action, including medical interventions, surgical options, and regular screenings.

Treatment

The main treatment for familial adenomatous polyposis (FAP) is surgery to remove the affected tissue, as the condition often leads to colon and rectal cancer if left untreated. The polyps in the duodenum can be managed through careful monitoring and regular polyp removal. Other complications, such as duodenal polyps, periampullary polyps, gastric fundic polyps, desmoids, and other cancers, may require additional treatment. Since FAP is an inherited genetic condition, genetic testing and counseling are recommended for individuals and families at risk. Regular screening is essential for early detection and management of the condition and its complications.

Preparing for medical consultation

Preparing for an appointment regarding familial adenomatous polyposis (FAP) involves taking a few key steps:

1. Gather medical records: Collect any previous scans, X-rays, and medical records related to FAP or colon polyps. This information will be useful for the healthcare provider to understand your medical history.
2. List symptoms and personal information: Make a list of any symptoms you're experiencing, including any that may seem unrelated to FAP. Also, include key personal information, such as major stresses or recent life changes.
3. Medications and supplements: Create a list of all medications, vitamins, and supplements you're currently taking. This includes any prescription medications, over-the-counter drugs, and any herbal or dietary supplements.
4. Bring a support person: Consider bringing a family member or friend to the appointment for support and to help remember the information discussed during the appointment.
5. Prepare a list of questions: Compile a list of questions to ask the healthcare provider during the appointment. These may include questions about the diagnosis, treatment options, potential side effects, and any lifestyle changes recommended to manage FAP.
6. Be aware of pre-appointment restrictions: Confirm with the healthcare provider if there are any restrictions or preparations needed before the appointment, such as modifying your diet or fasting for certain tests. Remember to be open and honest with your healthcare provider about your concerns and symptoms. This information will help them provide the best possible care and guidance for managing FAP.