A hereditary colon cancer: Are you aware of HNPCC?

Have you ever heard that one, maybe two or three, members of your family have developed colon cancer? Or are you a little scared because you have a family history of cancer? In fact, some types of cancer can be passed down from generation to generation. Today we are going to talk about a special type of colon cancer that is passed down through our genes. We call this HNPCC.

What is HNPCC?

Simply put, HNPCC (Hereditary Nonpolyposis Colorectal Cancer) is a type of colon cancer that is caused by certain changes (mutations) in genes that are passed down through generations. This is a cancer that occurs in our large intestine (colon).

So is this the same as Lynch Syndrome?

You've probably heard Lynch Syndrome more often than HNPCC. The two are closely related, but not exactly the same. Think of it this way. Lynch Syndrome is a genetic defect in our bodies. It's a genetic condition that increases the risk of cancer.

HNPCC is the name given to a condition in which a person with Lynch Syndrome develops colon cancer or other related cancers (such as uterine or small bowel cancer), especially before the age of 50. HNPCC cancers most often develop in the right side of the large intestine.

How common is HNPCC? What are the symptoms?

HNPCC accounts for between 2% and 4% of all colorectal cancers reported worldwide. Although the condition can occur at any age, it is most often diagnosed in people under the age of 50.

HNPCC may not have any specific symptoms in the early stages, but as the cancer progresses, these symptoms may appear.

Why does HNPCC develop? Is it contagious?

The main reason for this is our genes. Think of our body as a building built according to a big plan. The book that contains that plan is our DNA. We call the instructions in this DNA genes.

People with Lynch Syndrome have a defect in several specific genes (`MLH1`, `MSH2`, `MSH6`, `PMS2` and `EPCAM`) that repair mistakes in DNA. When these genes don't work properly, mistakes in DNA (`DNA replication errors`) that occur when our cells divide are not corrected. Over time, these mistakes accumulate and a normal cell becomes more likely to become a cancer cell.

The important thing is that HNPCC is not a contagious disease. That means it is not spread from one person to another like a cold. However, the faulty gene that causes it can be passed down from generation to generation. That means if either parent has Lynch Syndrome, a child has a 50% chance of inheriting that gene. If they inherit that gene, that child has a higher risk of developing HNPCC or other related cancers in the future.

How does a doctor detect this?

If you have the symptoms mentioned above, especially if someone in your family has had colon cancer, you should definitely see a doctor.

The doctor will first examine you. Then, if colon cancer is suspected, the most common test is a colonoscopy . This involves inserting a thin tube through the anus and using a camera to examine the inside of the large intestine.

To confirm whether you have HNPCC, your doctor will also look for the following:

• Family cancer history: You will definitely be asked if anyone in your immediate family, such as your mother, father, or siblings, has ever had colon cancer or another cancer associated with Lynch Syndrome before the age of 50.
• Genetic Testing: A special blood test is recommended to determine if you have the genetic mutations that cause HNPCC.
• Ruling out other conditions: Like HNPCC, there is another hereditary colon cancer condition called FAP (Familial Adenomatous Polyposis) . Because there are differences between the two, tests will also be done to confirm that you have HNPCC and not FAP.

What is the difference between HNPCC and FAP?

Although both are hereditary conditions of colon cancer, the genes that cause them are different. The main difference is the number of polyps that develop in the colon.

What are the treatments for HNPCC?

The main treatment for HNPCC is surgery (colectomy) . This involves surgically removing the part or all of the colon where the cancer is located. This can be done in a variety of ways.

• Partial colectomy: Removal of only the part of the colon where the cancer is located.
• Total colectomy: Removal of the entire large intestine.
• Proctectomy: Removal of both the large intestine and rectum.

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

• Chemotherapy: A drug treatment that destroys cancer cells.
• Immunotherapy: Stimulating our body's own immune system to fight cancer cells.

In many cases, immunotherapy can be more successful for HNPCC cancer.

What is the future of someone with HNPCC?

Lynch Syndrome is a genetic condition that cannot be cured. It is a lifelong condition. However, surgery can cure HNPCC cancer and prevent future colon cancer.

A person with HNPCC is at risk of developing other types of cancer in addition to colon cancer. That's why your doctor will tell you to have regular screenings.

• Endometrial cancer
• Ovarian cancer
• Stomach cancer
• Kidney, brain, liver and skin cancer

On average, about 60% of people diagnosed with HNPCC survive for 5 years. And between 70% and 88% of people with bowel cancer due to Lynch Syndrome survive for more than 10 years. These statistics show how important early detection and treatment are.

What can be done to avoid and manage this risk?

There is no way to prevent the genetic mutation that causes this. It is something we inherit. However, there are many things you can do to prevent cancer or detect it early.

• Be aware of your family history: If someone in your family has Lynch Syndrome or HNPCC, talk to your doctor about it and ask if you need to get genetic testing as well.
• Start screening early: If you are diagnosed with Lynch Syndrome, your doctor will recommend that you start getting colon cancer screening (colonoscopy) in your 20s.
• A healthy lifestyle: These things help a lot in reducing the risk of cancer:
• Avoid smoking completely.
• Limit alcohol consumption.
• Eat a healthy diet rich in vegetables and fruits.
• Exercise regularly.
• Maintain a healthy body weight.
• Be aware of symptoms: If you develop any new symptoms, do not ignore them and see a doctor immediately.