Are you aware of FAP (Familial Adenomatous Polyposis), a disease that causes hundreds of polyps to form in the colon?

Has anyone in your family, especially at a young age, developed colon cancer? Or has a doctor told you that you have a lot of polyps in your colon? Perhaps this is due to a genetic condition that runs in families. Today we are going to talk about one such rare but very important condition. It is FAP, or Familial Adenomatous Polyposis. Although the name is a bit complicated, let's understand it simply.

Simply put, what is FAP?

FAP is a genetic condition that can be passed down from generation to generation. People with this condition develop large numbers of tumors called adenomas , which can develop into cancer, in their colon and rectum.

Now you may be thinking, "Is it normal to have a cyst on your colon?" Yes, it's normal for some people to develop one or two of these cysts as they age. But someone with FAP can develop hundreds, maybe even thousands, of these cysts. And it starts at a very young age , maybe as young as 15 or 16 years old.

These polyps are not cancerous at first. But they are called 'precancerous'. This means that if left untreated, there is a very high risk that one or more of these polyps will eventually develop into colorectal cancer .

Without this surgery, most people with FAP will likely develop cancer in middle age. Also, people with FAP are at risk of developing tumors not only in the colon but also in other parts of the body (for example, the stomach, small intestine, skin, and bones). Therefore, even after the colon is removed, they will need regular medical checkups throughout their lives.

What is the risk of cancer with FAP?

If left untreated, FAP has a nearly 100% chance of developing colon cancer. This is a very serious condition. People with FAP develop cancer at a much earlier age and at a faster rate than the average person. Therefore, if you know there is a family history of FAP, your child should have a colonoscopy every year starting at age 10.

In addition to colon cancer, people with FAP are also at risk of developing other types of cancer.

Are there different types of FAPs?

Yes, there is a main type of FAP and several sub-types that are slightly different and less severe. Let's see what they are.

What is the difference between FAP and Lynch Syndrome?

Lynch syndrome is another genetic condition that can be passed down through generations and increase the risk of colon cancer. But there is a key difference between the two. People with Lynch syndrome don't develop hundreds of polyps, as they do in FAP. Sometimes, one or two polyps develop, and they can quickly become cancerous. That's why Lynch syndrome is sometimes called a "nonpolyposis" condition. Both conditions are caused by defects in different genes.

What are the symptoms of FAP?

In FAP, colon tumors begin to develop much earlier than in the general population, often at a younger age. These tumors often do not cause any symptoms until they are dangerously large. That is why screening is so important.

However, because the number of cysts is so large and they grow rapidly, sometimes symptoms can appear. Such symptoms include:

• Rectal bleeding
• Persistent diarrhea
• Chronic abdominal pain

In addition to this, people with FAP may also have external symptoms that a doctor can easily observe.

• Dermatofibromas: Hard, scar-like lumps that form under the skin.
• Epidermal cysts: Spherical lumps filled with keratin that form under the skin.
• Osteomas: Noncancerous tumors that form in the bones. These are often found in the skull or pelvis.
• Extra teeth or impacted teeth: These can be detected with a dental X-ray.
• Pigmented retinal spots (CHRPE): These can be seen during an eye exam. However, they usually do not affect vision.

What is the main cause of FAP?

As we mentioned earlier, FAP is caused by a gene mutation. The gene that affects this is called the APC (Adenomatous Polyposis Coli) gene.

A person with FAP has a mutated APC gene, meaning it's defective. Then, like a car with broken brakes, cells divide uncontrollably and form hundreds of tumors.

This genetic defect is inherited. If one of the parents has this APC gene mutation, the child has a 50% chance of inheriting it . This means that each child may or may not develop it. However, about 30% of people diagnosed with FAP have no family history. This means that this genetic defect has arisen in their body recently (original mutation).

What are the possible complications of FAP?

The most important and dangerous complication to manage with FAP is colon cancer . This risk is greatly reduced when the colon is surgically removed. However, there are some difficulties with living without a colon. The bowel movement process is changed. For this, an ileostomy pouch or ileal pouch may be used.

Because the APC gene defect is present in every cell in the body, tumors can also form outside the intestine. Some of these have the risk of becoming cancerous.

• Duodenal polyps: These develop in almost everyone with FAP. A small number of these can develop into cancer of the duodenum, bile duct, or pancreatic duct.
• Stomach polyps: Occur in about 90% of people, but only a small percentage, about 1%, develop into cancer.
• Desmoid tumors: These are not cancerous. But they can be very aggressive and can spread to nearby organs and blood vessels, damaging them. They are difficult to remove and can come back.
• Thyroid cancer: This can occur in about 2% of people with FAP. These are often completely curable.
• Liver cancer: Children with FAP, in particular, have a small risk of developing a rare liver cancer called hepatoblastoma .

How is it treated and managed?

The treatment plan for FAP can be divided into two parts: surgery and lifelong testing.

1. Surgery

Most people with classic FAP will need to have a total colectomy, which involves removing the entire colon, in their 20s or early 30s. Your doctor will decide when and how to perform this surgery, based on your condition.

2. Regular screening

You will have to undergo various tests before and after surgery, throughout your life. This is the best way to protect your life.

How is life with FAP?

It's normal to feel sad and shocked when you learn that you have a genetic condition like this. However, knowing about this condition early is the best way to manage your cancer risk.

With proper medical care and regular checkups, someone with FAP can live a normal, long, healthy life . After the colon is removed, the biggest risk comes from other cancers of the gastrointestinal tract or desmoid tumors. But these are much rarer than colon cancer.

Although surgery is a major life change, with today's advanced technology, laparoscopic surgery can help you recover faster.

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