Familial Adenomatous Polyposis (FAP) ( Disease & Conditions, Treatments & Procedures , Symptoms )
The lining of the large intestine and the rectum develop numerous polyps (tiny growths) as a result of the hereditary condition known as familial adenomatous polyposis (FAP). The possibility of having colorectal cancer at a young age is increased by the possibility that these polyps would eventually develop into cancer.
The APC gene, which typically aids in inhibiting the growth of polyps, causes FAP. A person only needs to inherit one mutant copy of the APC gene from one parent to become unwell because the ailment is inherited in an autosomal dominant fashion.
Abdominal pain, altered bowel habits, blood in the stool, and unexplained weight loss are a few of the signs and symptoms of FAP. Genetic testing, imaging analysis, and physical tests are frequently used in diagnosis.
The colon or rectum may occasionally need to be surgically removed, even though colonoscopies are frequently performed to check on FAP patients and remove polyps. In order to establish their risk of passing the condition on to their offspring, it may also be suggested that people with FAP receive genetic counseling and testing.
This article covers the following topics :
Familial adenomatous polyposis (FAP): What is it?
The rectum and the lining of the large intestine grow many polyps as a result of the uncommon genetic condition known as adenomatous polyposis (FAP). The possibility of having colorectal cancer at a young age is increased by the possibility that these polyps would eventually develop into cancer.
The APC (adenomatous polyposis coli) gene, which typically aids in inhibiting the growth of polyps, causes FAP. A person only needs to inherit one mutant copy of the APC gene from one parent to become unwell because the ailment is inherited in an autosomal dominant fashion.
If FAP is not treated, a person has a 100% chance of acquiring colorectal cancer, which often manifests before the age of 40. Additional cancers that are more likely to harm people with FAP include thyroid, pancreatic, and stomach cancer.
Abdominal pain, altered bowel habits, blood in the stool, and unexplained weight loss are a few of the signs and symptoms of FAP. Many FAP sufferers, however, might not show any symptoms until the polyps are huge or malignant.
Physical examination, imaging procedures (such as colonoscopies or CT scans), and genetic testing to confirm the existence of APC mutations are frequently used to diagnose FAP.
FAP is often treated with frequent monitoring and colonoscopies to remove polyps. This can lower the risk of getting cancer and may even stop it from starting altogether. If the polyps grow too large or cancer is found, the colon or rectum may occasionally need to be surgically removed.
In order to establish their risk of passing the condition on to their offspring, it may also be suggested that people with FAP receive genetic counseling and testing. For families where the FAP mutation is known, prenatal testing may be an option.
For the purpose of improving FAP prevention and therapy, research is ongoing. Two recent medications that have showed promise in lowering the quantity and size of polyps in FAP patients are celecoxib and sulindac. Immunotherapy and other targeted therapies are also being studied in clinical trials for persons with malignancies linked to FAP.
In conclusion, Familial Adenomatous Polyposis (FAP), a hereditary condition that increases the risk of colorectal cancer by causing the growth of many polyps in the large intestine and rectum. Regular monitoring and colonoscopy-based polyp removal are the norm; in more severe circumstances, surgery may be an option. For FAP sufferers and their families, genetic testing and counseling may also be recommended.
Familial adenomatous polyposis (FAP): what causes it?
APC (adenomatous polyposis coli) gene mutations are the root cause of familial adenomatous polyposis (FAP). In the rectum and large intestine, the APC gene often helps to prevent the growth of polyps.
In FAP patients, the APC gene’s normal function is disrupted, which promotes polyp growth and multiplication. The risk of colorectal cancer is increased by the potential for some of these polyps to develop into cancer over time.
Because FAP is inherited autosomally dominantly, all that is required for a person to develop the condition is one copy of the APC gene from one parent. As a result, there is a 50% probability that each of a parent’s offspring who also has FAP will receive the disease-causing gene.
Rarely, mutations in other genes involved in repairing DNA damage, like MUTYH or POLE, can also cause FAP. These occurrences do not happen as frequently as FAP associated to APC, though.
FAP is caused by a genetic mutation, although not everyone who inherits the mutation will develop the condition. Some persons with FAP may never experience any symptoms, while others may have a less severe condition with fewer polyps. Even within families who share the same genetic mutation, the severity of the ailment might differ greatly.
What precisely are desmoid tumors?
Desmoid tumors are uncommon, non-cancerous growths that develop from connective tissue cells. They are also known as aggressive fibromatosis or desmoid-type fibromatosis. Although these tumors can develop in practically any area of the body, the abdomen, pelvis, and shoulder girdle are where they most frequently occur.
Desmoid tumors can be classified as either sporadic or inherited. Those with familial desmoid tumors, such as those with Gardner syndrome, are affected while those with sporadic desmoid tumors, which do not run in families, do not. A uncommon genetic condition called Gardner syndrome can result in many polyps in the colon and rectum, as well as other benign growths such desmoid tumors.
It is unclear what particularly triggers desmoid tumors. On the other hand, the APC (adenomatous polyposis coli) gene mutation has been linked to an increased risk of spontaneous desmoid cancer. Familial Adenomatous Polyposis (FAP), a disorder that encourages the growth of many polyps in the colon and rectum, is caused by a mutation in this gene.
Desmoid tumors typically have a modest rate of growth, but they can become aggressive locally and infiltrate nearby organs and tissues, which can cause discomfort, dysfunction, and deformity. The size, location, and aggressiveness of the tumor determine the potential treatments for desmoid tumors.
Active surveillance could be suggested in some circumstances, especially for tiny or asymptomatic malignancies. Normally, desmoid tumors are removed surgically, but occasionally this is not possible without seriously harming the tissues and organs nearby. If surgery is not an option, radiation therapy might be used to treat the tumor or to reduce it before surgery.
For patients with unresectable, aggressive, or recurrent desmoid tumors, systemic therapy with nonsteroidal anti-inflammatory medications (NSAIDs), hormone therapy, chemotherapy, and targeted therapy may also be taken into consideration.
Most patients have a fair prognosis, and desmoid tumors typically neither progress nor return. To find and treat any recurrent or new tumors, however, long-term surveillance and follow-up are required due to the high risk of recurrence.
How is familial adenomatous polyposis (FAP) inherited?
A single copy of the mutated APC (adenomatous polyposis coli) gene acquired from one parent is the source of familial adenomatous polyposis (FAP), which is inherited in an autosomal dominant way.
Each gene is normally inherited twice, once from each parent. One mutant copy of the gene is all that is required for a person to have the condition in autosomal dominant inheritance. As a result, there is a 50% probability that each of a parent’s offspring who also has FAP will receive the disease-causing gene.
FAP is not a guarantee in people with the mutant APC gene, and this is a crucial point to remember. Some people may only have a few polyps, whilst others may have hundreds or thousands, depending on the penetrance of the mutation.
Given that FAP is an inherited ailment, genetic testing and counseling are advised for anyone who has a family history of the disorder or is exhibiting symptoms. Genetic counseling can help people and families understand the risks and available treatments for the illness. Genetic testing can demonstrate whether a person has inherited the mutant APC gene.
How is familial adenomatous polyposis, or FAP, discovered?
The diagnosis of familial adenomatous polyposis (FAP) frequently involves a concoction of clinical assessment, medical history, and genetic testing.
If there are several adenomatous polyps present, the colon and rectum may exhibit FAP symptoms. Signs of stomach pain or distension may be visible upon physical examination. To ascertain the extent of the polyps and check for any potential issues, a CT scan or MRI may also be carried out.
The diagnosis of FAP must include genetic testing. This entails examining a blood or saliva sample for APC (adenomatous polyposis coli) gene alterations. Genetic testing may also be carried out on those with a family history of the disorder to identify those who are most at risk of developing FAP.
Rarely, even when genetic testing is negative, a diagnosis of FAP may be obtained solely based on clinical data. Some requirements include having adenomatous polyps in the colon and rectum, having a family history of FAP or colorectal cancer, and having morphological characteristics such desmoid tumors and congenital hypertrophy of the retinal pigment epithelium (CHRPE).
FAP requires ongoing diagnosis and treatment to halt polyp growth and lower the risk of colorectal cancer. To achieve this, it may be necessary to undergo numerous colonoscopies, imaging tests, drugs to slow polyp growth, and, in some cases, surgery to remove polyps or the colon and rectum.
What is the treatment for familial adenomatous polyposis (FAP)?
Treatment for Familial Adenomatous Polyposis (FAP) depends on the number and size of the polyps, the patient’s age and general health, as well as additional variables such the presence of desmoid tumors.
Delaying the beginning of colorectal cancer is the main objective of FAP treatment. Regular colonoscopies, imaging studies, and drugs to stop polyp growth may be required as a result. It may occasionally be essential to undergo surgery to remove polyps from the colon and rectum in order to lower the risk of cancer.
Nonsteroidal anti-inflammatory medications (NSAIDs), COX-2 inhibitors, and selective estrogen receptor modulators (SERMs) may be used to reduce the growth of polyps in the colon and rectum. Usage of these drugs is frequently followed by intensive observation and monitoring.
If the polyps are excessively numerous, big, or develop malignancy, surgery can be required. In most cases, FAP patients need a colonoscopy, which involves the removal of the whole colon and rectum. The colon and rectum can be removed, and a pouch from the small intestine can be made and linked to the anus during a procedure known as a proctocolectomy with ileal pouch-anal anastomosis (IPAA). This enables regular bowel function and eliminates the need for a permanent ostomy.
Patients with FAP may additionally need surveillance and treatment for disorders like desmoid tumors and congenital hypertrophy of the retinal pigment epithelium (CHRPE), in addition to monitoring and care for the colon and rectum.
As they can aid in identifying at-risk family members and offer advice on screening and prevention methods, genetic counseling and testing are also crucial components of managing FAP.
In order to provide patients with the greatest outcomes, treating FAP necessitates a multidisciplinary approach comprising gastroenterologists, surgeons, genetic counselors, and other experts.
What is involved in surgery for familial adenomatous polyposis (FAP)?
Surgery is frequently used to treat Familial Adenomatous Polyposis (FAP) when the polyps are excessively many, big, or have turned cancerous. The size of the polyps and if cancer has manifested influence the kind of surgery that is carried out.
In most cases, FAP patients need a colonoscopy, which involves the removal of the whole colon and rectum. By removing every tissue where it can grow, this surgery completely eliminates the risk of colorectal cancer. The colon and rectum can be removed, and a pouch from the small intestine can be made and linked to the anus during a procedure known as a proctocolectomy with ileal pouch-anal anastomosis (IPAA). This enables regular bowel function and eliminates the need for a permanent ostomy.
If the polyps have spread outside of the colon and rectum, more gastrointestinal organs may need to be removed during FAP surgery. For instance, surgery to remove polyps from the duodenum (the first part of the small intestine) may be required.
Following surgery, patients with FAP will need continued surveillance and monitoring to look for any possible polyp or cancer recurrence. Regular colonoscopies, imaging exams, and other screening procedures can be necessary for this.
It’s crucial to understand that FAP cannot be surgically treated because polyps may still form throughout the gastrointestinal tract. Therefore, to avoid the onset of cancer and other problems, patients with FAP will need continued therapy and observation throughout their lifetimes.
What drugs are effective in treating familial adenomatous polyposis (FAP)?
Familial Adenomatous Polyposis (FAP) can be controlled with medication, especially if it slows the growth of polyps in the colon and rectum. These drugs can be used either on their own or in conjunction with other therapies like surgery and strict monitoring.
A class of drugs known as NSAIDs is frequently prescribed to relieve pain and inflammation, but they can also be useful in FAP to stop the development of polyps. Cyclooxygenase (COX), an enzyme involved in polyp growth and development, is inhibited by NSAIDs. Celecoxib and sulindac are both NSAIDs that have been used to treat FAP.
A different class of drugs called selective estrogen receptor modulators (SERMs) may be used to treat FAP. These medications counteract estrogen’s physiological effects, which can halt the growth of polyps in the colon and rectum. A SERM that is frequently used to treat FAP is tamoxifen.
A more contemporary class of NSAIDs called COX-2 inhibitors was created specifically to restrict the activity of the COX-2 enzyme, which plays a role in inflammation and the growth of polyps. A COX-2 inhibitor called celecoxib is used to treat FAP.
It’s critical to remember that although drugs may be useful in reducing polyp growth, they do not treat FAP. To stop the onset of cancer and other problems, patients with FAP will need continual therapy and monitoring for the rest of their lives. The medicine choice and dose will be based on the patient’s particular medical needs, the severity of their polyps, and other variables. A healthcare practitioner should keep a close eye on the treatment plan.
What is an upper gastrointestinal endoscopy for familial adenomatous polyposis (FAP)?
An upper gastrointestinal endoscopy is a procedure that allows medical practitioners to examine the esophagus, stomach, and duodenum (the first portion of the small intestine) in the upper GI tract. Given that polyps can grow in the upper GI tract in addition to the colon and rectum, this therapy is frequently utilized in the surveillance and management of familial adenomatous polyposis (FAP).
A long, flexible tube with a camera and light on the end is passed through the mouth into the esophagus, stomach, and duodenum during an upper gastrointestinal endoscopy. The camera enables the medical expert to see the GI system’s lining and see any polyps or other anomalies.
A biopsy (a small sample of tissue) may be performed if polyps are found during the surgery in order to do additional study. This can assist in identifying the type of polyp and whether it is malignant or benign.
Although upper GI endoscopy is typically a risk-free operation, there are some possible hazards, including bleeding, perforation (a hole in the GI tract), and sedation-related adverse effects. Before the procedure, patients should go over these risks with their surgeon.
Upper GI endoscopy, which makes it possible to find and remove polyps in the upper GI tract early on, is generally beneficial for the monitoring and therapy of FAP. In order to check for any potential polyps or cancer, patients with FAP should receive routine endoscopic screening in addition to further imaging testing and surveillance.
Definition of “familial adenomatous polyposis thyroid” (FAP thyroid).
Familial adenomatous polyposis (FAP), a genetic illness, is characterized by the development of many polyps in the colon and rectum. However, it’s also possible that FAP sufferers have a higher risk of getting other cancers, like thyroid tumors.
Thyroid tumors affect roughly 2-5% of FAP patients, which is a relatively low incidence. Malignant (cancerous) or benign (non-cancerous) tumors are both possible. Papillary thyroid carcinoma is the most common type of thyroid tumor in FAP, while other types can also occur.
It is believed that the genetic mutation in the APC gene, which causes FAP, is what contributes to the greater risk of thyroid cancer in FAP patients. This mutation has the potential to harm the thyroid gland as well as other human organs.
Due to the minimal chance of acquiring these tumors, routine thyroid tumor screening is generally not recommended for persons with FAP. Routine thyroid monitoring may be necessary, nevertheless, if a person with FAP has a family history of thyroid cancer or other risk factors, like radiation exposure.
The type and stage of the thyroid tumor that is discovered in a patient with FAP will affect the treatment plan. While benign tumors can frequently be followed with regular imaging, malignant tumors may necessitate surgery, radiation therapy, and/or chemotherapy.
Patients with FAP seldom develop thyroid tumors, but they should be aware of this potential risk and talk to their doctor if they have any worries. Additionally, routine screening for any potential FAP side effects, such as colon cancer, is advised.