Familial Adenomatous Polyposis (FAP): Symptoms, Causes, Treatment

What are the symptoms of familial adenomatous polyposis?

Familial adenomatous polyposis (FAP) is a genetic condition characterized by the development of hundreds to thousands of polyps in the colon and rectum. Symptoms can vary depending on the number and size of polyps, but they may include:

1. Rectal bleeding: Often the earliest sign, caused by bleeding from the polyps.
2. Abdominal pain: Cramping or dull aches may occur, especially if polyps are large.
3. Diarrhea or constipation: Changes in bowel habits can occur.
4. Anemia: Due to chronic blood loss from the polyps.
5. Unexplained weight loss: Can occur in more advanced cases.
6. Fatigue: Related to anemia or the disease process itself.
7. Bowel obstruction: Rare, but can occur if polyps are large enough to block the bowel.

It’s important to note that many individuals with FAP are asymptomatic until the polyps are discovered during screening exams. Regular screenings, such as colonoscopies, are crucial for early detection and treatment.

What are the causes of familial adenomatous polyposis?

Familial adenomatous polyposis (FAP) is caused by mutations in the APC (adenomatous polyposis coli) gene, which is a tumor suppressor gene. This mutation is inherited in an autosomal dominant pattern, meaning that a person only needs to inherit one copy of the mutated gene from either parent to develop the condition.

The APC gene normally helps regulate cell growth and division. Mutations in this gene lead to uncontrolled cell growth and the formation of multiple adenomatous polyps in the colon and rectum, which are benign growths that can become cancerous over time if not treated.

In some cases, FAP can also occur as a result of a new mutation in the APC gene, rather than being inherited from a parent. These cases are known as sporadic FAP. However, the majority of FAP cases are inherited from a parent with the mutated gene.

How is the diagnosis of familial adenomatous polyposis made?

The diagnosis of familial adenomatous polyposis (FAP) is typically made based on a combination of clinical findings, family history, and genetic testing.

1. Clinical Evaluation: A physician may suspect FAP based on symptoms such as rectal bleeding, abdominal pain, or a family history of FAP or colon cancer. A physical examination may also reveal the presence of multiple polyps in the colon or rectum.
2. Colonoscopy: A colonoscopy is a procedure that allows a doctor to examine the inside of the colon and rectum. It is the most reliable way to diagnose FAP and to determine the number and size of polyps present.
3. Genetic Testing: Genetic testing can confirm the presence of a mutation in the APC gene, which is characteristic of FAP. This test can also be used to determine if family members are at risk for inheriting the condition.
4. Imaging Studies: In some cases, imaging studies such as CT scans or MRI scans may be used to assess the extent of polyp growth or to look for signs of cancer.
5. Family History: A detailed family history is important, as FAP is an inherited condition and tends to run in families. Knowing if other family members have had FAP or colon cancer can help in making a diagnosis.

Once a diagnosis of FAP is confirmed, regular monitoring and screening for colorectal cancer are typically recommended, as individuals with FAP have a significantly increased risk of developing cancer in the colon or rectum.

What is the treatment for familial adenomatous polyposis?

The treatment for familial adenomatous polyposis (FAP) typically involves a combination of surveillance, medication, and surgery. The goals of treatment are to prevent or delay the development of colorectal cancer and to manage symptoms associated with the condition. Here are some common approaches:

1. Surveillance: Regular colonoscopies are essential for monitoring the development of polyps and detecting any signs of cancer early. The frequency of colonoscopies depends on the number and size of polyps present.
2. Medication: Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin or celecoxib may be recommended to help reduce the number and size of polyps in some cases. However, long-term use of these medications can have side effects and should be carefully monitored.
3. Surgery: Surgical removal of the colon (prophylactic colectomy) is often recommended for individuals with FAP to prevent the development of colorectal cancer. This surgery may be done in stages, particularly if there are a large number of polyps. In some cases, surgery to remove the rectum (proctectomy) may also be necessary.
4. Genetic Counseling: Since FAP is an inherited condition, genetic counseling is recommended for individuals with FAP and their families. This can help assess the risk of passing the condition to future generations and provide information about available genetic testing and screening options.
5. Lifestyle Changes: Adopting a healthy lifestyle, including a balanced diet high in fruits, vegetables, and whole grains, regular exercise, and avoiding smoking and excessive alcohol consumption, can help reduce the risk of developing colorectal cancer.
6. Follow-Up Care: Regular follow-up visits with a healthcare provider are important for monitoring the effectiveness of treatment, managing any complications, and addressing any new symptoms or concerns.

The specific treatment plan for FAP will vary depending on the individual’s age, overall health, and the extent of the condition. It’s important for individuals with FAP to work closely with a healthcare team experienced in managing this condition to develop a personalized treatment plan.

What is the survival rate for familial adenomatous polyposis?

Familial adenomatous polyposis (FAP) is a genetic disorder characterized by the growth of numerous adenomas (adenomatous polyps) in the colon and rectum. If left untreated, these polyps can progress to colon cancer, which is often fatal if not detected early.

The survival rate for FAP depends on several factors, including the age of diagnosis, the number and size of polyps, and the effectiveness of treatment. Here are some general statistics:

1. Untreated FAP: Without treatment, the overall survival rate for individuals with FAP is approximately 30-40% by age 50. This is because most people with untreated FAP will develop colon cancer, which is often diagnosed at an advanced stage and has a poor prognosis.
2. Early detection and treatment: When FAP is detected and treated through regular colonoscopy and polyp removal, the survival rate improves significantly. In one study, the 10-year survival rate for individuals with FAP who underwent timely and effective treatment was approximately 95%.
3. Colectomy: A colectomy (removal of the colon) can significantly improve survival rates for individuals with FAP. In one study, the 10-year survival rate for patients who underwent colectomy was around 80%.
4. Genetic testing and risk reduction: Genetic testing can help identify individuals with FAP and allow for early intervention and risk reduction measures. Studies have shown that individuals who undergo genetic testing and implement preventive measures, such as regular colonoscopy and polyp removal, can have a survival rate similar to that of the general population.

Overall, early detection, treatment, and risk reduction measures can significantly improve the survival rate for individuals with familial adenomatous polyposis. It’s essential for individuals with a family history of FAP or those who have already been diagnosed to work closely with their healthcare providers to develop a personalized management plan.