Hereditary risk of colon cancer (HNPCC) - let's talk about this

Have you heard that several members of your family have developed colorectal cancer, especially before the age of 50? Or is there a high incidence of uterine cancer among women in your family? It's normal to feel a little scared and worried when we hear things like this. But it's more important than being scared to be aware of this. Today we're going to talk about a special cancer risk condition that can be passed down from generation to generation. We call this HNPCC.

What exactly is HNPCC?

Simply put, HNPCC is an acronym for Hereditary Nonpolyposis Colorectal Cancer . In Sinhala, it means something like "Hereditary Nonpolyposis Colorectal Cancer." But those words are very complicated, aren't they? So let's just remember it as HNPCC.

This is a cancer risk that can be inherited from generation to generation due to certain changes (mutations) in our genes. This mainly affects the large intestine, which is the last part of your intestine. But the name "Nonpolyposis" means "non-polyposis". The reason for this is that, usually, small growths called "polyps" form in the intestine before colon cancer develops. However, a person with HNPCC does not develop a large number of such polyps, but has a higher risk of cancer.

So is Lynch syndrome also HNPCC?

Yes, these two names are often used for the same condition. But there is a slight technical difference. Lynch syndrome is the genetic condition that causes it. That is, if someone has a gene mutation related to Lynch syndrome, they have a higher risk of developing a cancer condition called HNPCC.

Generally, if a person under the age of 50 develops a cancer associated with Lynch syndrome, such as colon cancer, endometrial cancer, small intestine cancer, or ureteral cancer, the family is said to have a condition called HNPCC. These cancers most commonly develop in the right side of the large intestine.

How common is this condition? What are the symptoms?

HNPCC accounts for 2% to 4% of all colorectal cancers worldwide. This means that about 2 to 4 out of every 100 colorectal cancers are caused by this genetic factor. Although it can affect anyone, it is most often diagnosed in people under the age of 50.

In the early stages, HNPCC often doesn't cause any symptoms. That's the scariest part. But as the cancer gets bigger, you may start to experience symptoms like these.

Why does HNPCC develop? Is it contagious?

The main reason for this is our genes. Imagine that our body is like a big book, and genes are the instructions written in that book. Every cell in our body works according to these instructions. Sometimes, there are spelling mistakes (mutations) in these instructions.

Our bodies normally have special genes that can recognize and correct these mistakes. It's like someone proofreading a book. In Lynch syndrome, there is a defect in these "correction" genes, MLH1, MSH2, MSH6, PMS2, and EPCAM . Then, when cells divide, they can't correct other mistakes. Over time, these cells with these errors accumulate and become cancer cells.

This is not a contagious disease. You cannot catch it by eating food or being with someone who has HNPCC. However, the gene mutation that causes it can be passed down from generation to generation. Imagine that either the mother or the father has this gene mutation. Then there is a 50% chance that one of their children will inherit that gene. That means that if there are two children, one of them can inherit this risk gene. That is why several people in such families develop cancer.

How does a doctor diagnose HNPCC?

When you go to see a doctor with the symptoms you mentioned above, the first thing he or she will do is listen carefully to your symptoms and do a physical examination. Then, they will ask a lot of questions about your family's medical history .

• "Have your mother, father, siblings had cancer?"
• "If so, what kind of cancer was it? At what age did it develop?"
• "How many people in your family have had cancer?"

These questions are very important because if several family members have had colon or uterine cancer, especially at a young age, the doctor may suspect HNPCC.

Next, the main test to confirm whether you have colon cancer is a colonoscopy . This involves examining your entire colon using a tube with a small camera attached. If anything suspicious is found, a small piece of tissue is taken and sent to a lab for testing (a biopsy).

To confirm HNPCC status, several special tests are required:

1. Genetic Testing: A sample of your blood is taken and tested for genetic mutations associated with Lynch syndrome.

2. Tumor tissue testing: If there is cancer, the cancer cells are tested for specific markers related to HNPCC.

3. Ruling out other conditions: There is another hereditary condition called Familial Adenomatous Polyposis (FAP) . In FAP, hundreds or thousands of polyps develop in the colon. This does not happen in HNPCC. So, your doctor will check to see which of these two conditions you have.

What are the treatments for HNPCC?

If colon cancer develops due to HNPCC, the main treatment is surgery to remove the cancer and surrounding tissue. This surgery is called a colectomy . It can be done in different ways.

• Partial Colectomy: Only the part of the colon where the cancer is located is removed.
• Total Colectomy: This surgery removes the entire colon. This surgery is often recommended for people with HNPCC to reduce the risk of developing another cancer in the future.
• Proctectomy: The rectum is removed along with the large intestine.

Other treatments

If the cancer has spread (metastasized) to other parts of the body, other treatments may be needed in addition to surgery.

• Chemotherapy: Giving powerful drugs to destroy cancer cells.
• Immunotherapy: Stimulating our body's own immune system to fight cancer cells. This treatment is often successful for cancers caused by HNPCC.

Things someone living with HNPCC should know

If you are diagnosed with HNPCC, it means that you are at higher risk than the average person of developing not only bowel cancer, but also several other types of cancer. Therefore, regular medical check-ups should be a part of your life.

Your doctor may advise you to get screened regularly for these cancers:

• Uterus
• Ovarian
• Stomach
• Kidney and urinary system
• Brain
• Skin

This may sound scary. But the best thing here is early detection . With regular screening, even if cancer starts to develop, it can be caught at a much earlier stage. Then the chances of being treated and completely cured are much higher.

Lynch syndrome cannot be cured, as it is something that is in our genes. However, cancers caused by HNPCC can be cured. Surgery such as a total colectomy can also prevent colon cancer.

How do I manage my risk?

If you have a family history of HNPCC or Lynch syndrome, the first thing you should do is talk to your doctor about it. He or she will decide if you need to undergo genetic testing.

If you are confirmed to have the Lynch syndrome gene mutation, your doctor will probably advise you to start screening for colon cancer, such as colonoscopies, in your 20s.

In addition, you can further reduce your risk of cancer by maintaining a healthy lifestyle:

• Avoid smoking completely.
• Eat a balanced, nutritious diet (include more vegetables, fruits, and fiber-rich foods).
• Exercise regularly.
• Limit alcohol consumption.
• Maintain a healthy body weight.
• Get all the tests recommended by the doctor done on time.

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