Familial adenomatous polyposis (FAP, familial polyposis) is a hereditary disease that affects the colon and causes polyps to grow, unchecked, in the bowel’s lining. Most patients with FAP have inherited “a defect in the adenomatous polyposis coli (APC) gene,” according to Mayo Clinic. However, as we’ve discussed in previous pages and posts about FAP, about a quarter of FAP patients don’t have a family history of the disease. Let’s take a look at some of our patient’s most common questions, including covering the early signs of familial polyposis, FAP life expectancy, and what causes familial adenomatous polyposis.
Our Eight Most Common Questions About FAP
#1: How Common Is FAP?
According to one study, “FAP occurs in 1 in 10000 individuals and is the second most common inherited colorectal cancer syndrome.” Furthermore, FAP seems to affect females and males equally.
#2: What Causes Familial Adenomatous Polyposis?
We often get asked this question here at the Colorectal Clinic of Tampa Bay: what causes familial adenomatous polyposis? FAP is primarily an inherited disorder, originating from a mutation in the APC gene on the fifth chromosome. This gene is a tumor suppressor gene that, in most individuals kills cancerous lesions before they even grow past a single cell. The fact that this gene functions improperly means that individuals with FAP may also develop tumors in other areas as well.
Gardner’s Syndrome
Since the APC gene makes up a large coded area, there are actually many opportunities for variance within this disease. In fact, the location of a patient’s mutation may make it more or less likely that the patient will develop polyps and cancerous masses outside the colon. Gardner’s Syndrome is a subset of FAP and can include problems with tooth impaction and bony cancers around the mandible and skull.
#3: Does FAP Skip Generations?
The APC mutation is passed to the next generation in an “autosomal dominant” (only one bad gene is required to cause disease) manner. Since patients with only one copy of the mutated APC gene will have symptoms, there is a 50% chance that the child of a FAP patient will be born with the mutation. For this reason, FAP can appear to skip generations. However, it is important to remember that some FAP patients have no family history of the disease and were born with a de novo (completely new) mutation.
#4: Are There Early Signs of Familial Polyposis?
Since the APC gene is responsible for so much more than stopping uncontrolled polyp growth in the colon, there are several warning signs that families with FAP in their history should look out for these early signs of familial polyposis:
Abnormal bumps and cysts on any part of the body.
Having teeth that do not come in when they should.
Spots that resemble freckles or hyperpigmented areas inside the eyelids.
#5: What Are the Symptoms of FAP?
Aside from the obvious overgrowth of polyps in a patient’s colon (visible in a colonoscopy), patients will also suffer from unexplainable or constant diarrhea, constipation, bloody stools, abdominal cramping, odd weight loss, vomiting, and nausea. FAP patients also develop cancer at an alarming rate; the likelihood of patients developing colon cancer by age 40 is 100%.
#6: What Is the Life Expectancy for a Patient With FAP?
FAP life expectancy depends on a few variables: how often you get screened for colon cancer, what treatment regimen you choose, and how early the disease is caught. As mentioned above, if left untreated and unmonitored, patients will develop life-threatening cancer by the age of 40. If the disease is caught early, patients who have a colonoscopy (or other monitoring procedure) once a year can stay on top of their disease. However, in patients who submit to regular monitoring, early cancer can be detected and steps can be taken to eliminate the problem.
In general, life expectancy for patients that do not undergo a colectomy is about 42 years. For patients that undergo a colectomy, life expectancy is that of a patient without FAP.
#7: Is FAP Curable?
FAP itself is caused by a genetic mutation; from a medical standpoint, FAP cannot be cured. However, by removing the colon, the manifestation of the disease can be severely limited if not removed entirely. The effectiveness of a colectomy will depend on where your APC mutation occurs on the gene.
#8: What Does FAP Treatment Involve?
The best treatment plan for FAP is the colectomy (complete removal of the colon). Most patients tend to put off this surgical procedure because it means that their way of life will change drastically. However, when the risks - developing life-threatening colon cancer - are so grave, most medical practitioners gently push for patients to have this procedure.
FAP Diagnosis and Treatment in Tampa Bay
If you have a family history of familial adenomatous polyposis, or you believe that you may have this disease, get in touch with a colorectal specialist as soon as possible. FAP life expectancy heavily relies on interventions and management. Contact our office if you are looking for a colorectal specialist in Tampa Bay.