Causes of colorectal cancer (colon and rectum)

Colorectal cancer is another term for cancer that attacks the large intestine (colon), rectum, or both. Based on WHO data in 2018, colorectal cancer ranks third for the most common types of cancer. So, do you know what causes cancer that attacks the colon and rectum?

What causes colorectal (colon and rectum) cancer?

Based on Globocan data in 2018, colorectal cancer ranks sixth in Indonesia and causes quite high mortality, namely 9,207 deaths from colon cancer and 6,827 deaths from rectal cancer.

The high, mortality rate is likely caused by late detection and diagnosis of colorectal cancer.

Until now, the cause of colorectal cancer (colon and / or rectum) is not known with certainty. However, in general, cancer occurs due to changes in the DNA in cells. These changes in DNA in cells are called DNA mutations.

DNA itself contains a series of instructions that tell the cell to function normally. As a result of this mutation, the cell's instructions are disorganized and damaged. Cells that are supposed to grow, divide, die programmatically, instead continue to grow and live out of control.

As a result, there will be a buildup of cells which over time forms a tumor. This mutation of cell DNA is the cause of almost all cancers, possibly in cancers that attack the large intestine (colon) or rectum (the end of the colon before the anus).

After the tumor has formed, it will continue to grow in size. In addition, cancer cells will also spread and damage the surrounding healthy tissues or organs. The spread of cancer cells from the initial site to other areas is known as cancer metastasis and the condition will cause a variety of colorectal cancer symptoms.

Various risk factors for colorectal cancer (colon and rectum)

The main cause of colorectal cancer is not known with certainty, but researchers have identified a variety of factors that can increase the risk. Some factors cannot be changed and continue to be owned by a person. Some of them can be changed by adopting a healthy lifestyle.

More specifically, let's talk one by one the factors that cause the increased risk of cancer of the colon and rectum.

1. Old age

Age is a risk factor for colorectal cancer. This is because cancer cells generally take years to become abnormal cells. Just like objects that you use every day, they will eventually get damaged. Well, the cells too so they can trigger cancer.

That is why, most people who have cancer cells are over 50 years old. Although, some of them can also have this disease at a young age.

2. A history of having colorectal polyps or cancer

In some people, the cause of increasing the risk of colon or rectal cancer is polyps. Polyps are small lumps that form in the large intestine, rectum, or other parts of the body. One type of polyp, namely adenomatous polyps have a high risk of turning into cancer if their size exceeds 1 cm.

Apart from colon polyps, the risk of this cancer is also quite high in people who have previously had colorectal cancer. Especially, in patients who developed the disease at a young age.

Not only your history of the disease, the risk also increases if there are family members who have the disease.

3. Have diabetes

Diabetes is dubbed the mother of all diseases. The reason is because this disease that causes blood sugar levels in a person to be uncontrolled can increase the risk of various diseases. Starting from heart disease, kidney problems, to cancer.

In a study published in Diabetes Spectrum , diabetes causes an increased risk of colon and rectal cancer because it causes inflammation that can damage cell DNA. This is because it is influenced by insulin resistance that occurs in the sufferer's body.

4. Have experienced intestinal inflammation

Apart from polyps, the cause of the high risk of cancer affecting the colon or rectum can also come from inflammation in the area. For example, ulcerative colitis or Crohn's disease. People with these two conditions, in the long term, will experience dysplasia.

Dysplasia is a medical term that describes the cells in the lining of the colon or rectum that look abnormal, but are not yet cancerous. Within a certain period of time, these cells can turn into cancer.

5. Genetic cancer syndrome

According to the American Cancer Society, about 5% of colorectal cancer cases are caused by cancer syndromes that run in families. Family cancer syndromes that cause a high risk of colon or rectal cancer, include:

Lynch Syndrome

This syndrome puts you at an 80 percent risk of developing colon or rectal cancer throughout her life. The disorder in people who are at risk of colon cancer is caused by a congenital defect gene, namely MLH1 or MSH2.

Apart from colon and rectal cancer, people with this syndrome are also prone to ovarian cancer, stomach cancer, kidney cancer, and breast cancer.

Familial adenomatous polyposis (FAP)

This syndrome is caused by mutations in the APC gene that are inherited from parents. FAP causes a person to have hundreds or even thousands of polyps in the colon and rectum, which generally range from 10 to 12 years of age.

By age 40, nearly everyone with FAP has colorectal cancer. FAP is divided into several types, namely Gardner's syndrome and Turcot's syndrome. Apart from colon cancer, both can also trigger other types of cancer in the body.

Another rare syndrome

There are many types of mutated genes that cause colorectal cancer, namely the STK11 gene that leads to Peutz-Jeghers syndrome (PJS) and the MYH gene that leads to MYH-associated polyposis (MAP) syndrome.

PJS causes a person to have many small polyps in the gastrointestinal tract. Meanwhile, MAP causes larger polyps in the gastrointestinal tract.

6. Obesity and lack of physical activity

Obesity is one of the causes of the high risk of colon and rectal cancer in a person. In fact, it complicates the treatment process so that cancer patients are required to maintain an ideal body weight.

The increased risk of cancer in a person due to obesity is caused by inflammation. Being overweight can lead to inflammation in the body which can damage cell DNA. In addition to body weight, people who are lazy to move also have an increased risk of cancer.

7. Poor diet

Food can be one of the causes of increasing the risk of colon or rectal cancer. To be precise, foods that contain carcinogenic ingredients, one of which is roasted beef or goat.

Even so, you can control the risk by reducing the consumption of burned foods. In addition, consumption of vegetables, fruit and whole grains can also increase the risk of cancer.

8. Smoking and drinking alcohol

Just like baked goods, alcohol and cigarettes also contain carcinogens. These substances can trigger inflammation and make cells in the body abnormal.

Not only in active smokers, the risk of cancer in the digestive system also increases in people who don't smoke but also inhale the smoke from burning cigarettes. Meanwhile, alcohol, the risk of cancer will increase if consumed in the long term and in large quantities.