Introduction
The causes of colon cancer are very diverse. In most cases, no specific cause can be identified afterwards. This is because it is usually an interplay of genetic and environmental factors.
Environmental factors are all things that affect a person from the outside. These include, for example, the living environment, nutrition or stress. However, there are also genetic diseases that greatly increase the risk of colon cancer. In addition, some risk factors are known to increase the risk of getting bowel cancer.
Overview of the most common causes of colorectal cancer
These are the most common causes of colon cancer:
- Genetic causes, such as FAP (Familial Adenomatous Polyposis)
- Smoking
- Food rich in fat and meat, low in fibre
- Alcohol
- Overweight and lack of exercise
- High age
- Diabetes mellitus type II
- Adenomas
- Persons who have themselves or close relatives who have other types of cancer, such as breast, ovarian or uterine cancer
Adenomas are the new formation of glandular tissue. Throughout the entire gastrointestinal tract the mucous membrane is interspersed with glands. Therefore, adenomas often develop in the gastrointestinal tract.
This new formation of glandular tissue can be slightly altered in contrast to the surrounding tissue, but in any case it is not malignant, but is called benign. However, the adenomas have a certain risk of degeneration, so that over time a cancer can develop from them. They are therefore also regarded as precursors of intestinal cancer.
Adenomas can be detected and, if necessary, removed during a colonoscopy, such as is performed during colon cancer screening. Often adenomas up to a certain size do not cause symptoms and are therefore not detected without a colonoscopy. Polyps are small outgrowths of the intestinal mucosa that protrude into the intestinal tract.
Some people have a lot of them. In old age, most people have one or more polyps. Polyps are benign and usually do not cause any symptoms.
However, over time a polyp can develop into an adenoma, which means there is a certain risk of degeneration. If a polyp is detected during a colonoscopy, it can be removed. This way, the risk of bowel cancer can be reduced with colonoscopy.
Crohn’s disease is one of the chronic inflammatory bowel diseases. In Crohn’s disease, recurring inflammations occur. All parts of the gastrointestinal tract can be affected by these inflammations.
Very often fistulas are formed. Fistulas are passages between the inside of the intestine and other organ cavities or the surface of the skin and can be very painful. Due to the many inflammatory processes, the tissue must always regenerate itself.
There is therefore a risk that mistakes will creep into these regeneration processes, leading to cancer. The risk of developing cancer depends on the location of the inflammation in the intestine. Ulcerative colitis is also a chronic inflammatory bowel disease.
In contrast to the disease, the inflammation in ulcerative colitis is limited to the large intestine and affects the entire colon. Here, too, the inflammation causes many remodelling processes in the mucous membrane, which increases the risk of developing intestinal cancer. About 5% of people suffering from ulcerative colitis develop colon cancer during the course of the disease.
Compared to Crohn’s disease, the risk of developing colon cancer is thus higher in ulcerative colitis. Being overweight is a risk factor for bowel cancer. It has been found that overweight people are more likely to get bowel cancer than people of normal weight.
Although the exact relationship has not yet been clarified, it is suspected that the link between obesity and the increased risk of bowel cancer is the altered hormone balance in the fatty tissue of overweight people. It is known that the fatty tissue increases the production of the hormone oestrogen. Furthermore, obesity is usually associated with a lack of exercise and poor nutrition.
Two factors which also have a negative effect on the intestines. In addition to many other cancers, nicotine abuse can also increase the risk of bowel cancer. Smoking a cigarette leads to a short-term deterioration in blood circulation and thus damages all organs.
One study found that smokers are much more likely to develop mucous membrane proliferations. However, the exact connection and which substances of the cigarettes lead to this process is not yet known. Various experts assume that lack of exercise increases the risk of colon cancer.
There are various hypotheses as to why exercise should have a protective effect on the bowel. Firstly, it is assumed that exercise promotes bowel activity. Secondly, higher insulin levels have been found in physically inactive people.
Under certain circumstances, this insulin has a negative effect on the intestinal mucosa. How can bowel cancer be treated? You can find out more at: Radiotherapy for Colon Cancer
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