What are the causes of colon cancer?


The causes of colon cancer are very diverse. In most cases, no specific cause can be identified afterwards. Because, as a rule, it is a question of an interplay between genetic factors and environmental factors. Environmental factors are all things that have an external effect on a person. This includes e.g. the living environment, the diet or even stress.
However, there are also genetic diseases that greatly increase the risk of colon cancer. Furthermore, some risk factors are known that increase the risk of developing colon cancer.

Overview of the most common causes of colon cancer

The most common causes of colon cancer are:

  • Genetic causes, e.g. FAP (familial adenomatous polyposis)
  • Smoke
  • Food rich in fat and meat, low in fiber
  • alcohol
  • Obesity and lack of exercise
  • Old age
  • Type II diabetes mellitus
  • Adenomas
  • People who have themselves or close relatives who have other types of cancer, such as Breast, ovarian, or uterine cancer

Also read our article: Is Colon Cancer Hereditary?

Adenomas as a cause of colon cancer

Adenomas are the formation of new glandular tissue. The mucous membrane in the entire gastrointestinal tract is permeated with glands. Therefore, adenomas often arise in the gastrointestinal tract. This new formation in glandular tissue can be slightly changed in contrast to the surrounding tissue, but is in any case not malignant, but is referred to as benign. However, the adenomas have a certain risk of degeneration, so that cancer can develop from them over time. They are therefore also considered to be the precursors of colon cancer.
Adenomas can be detected and, if necessary, removed as part of a colonoscopy, as is carried out in colon cancer screening. Often adenomas up to a certain size do not cause symptoms and are therefore not detected without a colonoscopy.

Polyps as a cause of colon cancer

Polyps are small protrusions on the lining of the intestine that protrude into the interior of the intestine. Some people have a great many 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 creates a certain risk of degeneration. If a colonoscopy detects a polyp in colon cancer screening, it can be removed. Colon cancer screening can reduce the risk of colon cancer.

Read more on the subject at: Colon polyps

Crohn's disease as a cause of colon cancer

Crohn's disease is a chronic inflammatory bowel disease.
In Crohn's disease, there is recurring inflammation. All parts of the gastrointestinal tract can be affected by this inflammation. Fistulas form very often. Fistulas are passages between the inside of the intestine and other organ cavities or the surface of the skin and can be very painful. Because of the many inflammatory processes, the tissue has to regenerate itself. This means that there is a risk that errors will creep in in these regeneration processes and that cancer will develop as a result. The risk of developing cancer depends on the location of the inflammation in the intestine.

Read more on the subject at: Fistulas in the intestines

Ulcerative colitis as a cause of colon cancer

Ulcerative colitis is also a chronic inflammatory bowel disease.
In contrast to disease, the inflammation in ulcerative colitis is limited to the large intestine and affects it across the board. Here, too, many remodeling processes take place in the mucous membrane due to the inflammation, which increases the risk of developing colon cancer. About 5% of people with ulcerative colitis develop colon cancer in the course of the disease. Compared to Crohn's disease, the risk of colon cancer in ulcerative colitis is higher.

Read more on the subject at: Symptoms of ulcerative colitis

Obesity as a risk factor for colon cancer

Obesity is a risk factor for colon cancer. It has been found that overweight people are more likely to develop colon cancer than people of normal weight.The exact connection has not yet been clarified, but it is assumed that the connection between obesity and the increased risk of colon cancer is the changed hormone balance in the adipose tissue of overweight people. It is known that adipose tissue increases the production of the hormone estrogen.
Furthermore, being overweight is usually associated with a lack of exercise and poor nutrition. Two factors that also have a negative effect on the intestines.

Nicotine as a risk factor for colon cancer

In addition to many other cancers, nicotine abuse can also increase the risk of colon cancer.
Smoking a cigarette leads to a short-term deterioration in blood circulation and thus damages all organs. A study found that smokers are much more likely to develop mucosal growths. However, the exact relationship and which substances in the cigarettes lead to this process are not yet known.

Read more on the subject at: Consequences of smoking

Sedentary lifestyle as a risk factor for colon cancer

Various experts assume that a lack of exercise increases the risk of colon cancer.
There are various hypotheses as to why exercise should have a protective effect on the intestine. For one, it is believed that exercise promotes bowel activity. On the other hand, higher insulin levels were found in physically inactive people. Under certain circumstances, this insulin has a negative effect on the intestinal lining.

How can you treat colon cancer? You can find out more at: Radiation therapy for colon cancer

What role does diet play in colon cancer?

To this day it is still unclear to what extent the connection between diet and the development of colon cancer is. However, it is estimated by some experts that around a third of colorectal cancer cases could have been prevented through a different lifestyle and diet. The exact interaction between the individual diets and nutritional factors is difficult to research scientifically. The role of fiber is a hot topic among scientists.
Many experts assume that the dietary fiber has a protective effect on the intestine and protects against colon cancer. The fiber shortens the passage time of the food porridge through the gastrointestinal tract, which means that toxins have less time in contact with the intestinal mucosa. Furthermore, dietary fiber leads to an early feeling of satiety and can thus contribute to maintaining a normal weight. It is also said that a low-meat diet also has a protective effect on the intestines.
If you already have colon cancer, it is also very important to pay attention to your diet. Chemotherapy and radiation therapy in particular rob the body of a lot of strength. It is therefore extremely important to ensure sufficient energy supply in this phase.

More on this: Diet in cancer

Can colon cancer be inherited?

There are several syndromes that are inherited and that are associated with an increased risk of colon cancer.
These include e.g. Lynch Syndrome and Gardner Syndrome. Even if no syndrome or disease such as familial adenomatous polyposis is known, genetically there may be an increased susceptibility to colon cancer. It is assumed that there is an increased risk of colon cancer in a family if relatives are known to have colon cancer before the age of 55.

Read more on the subject at: Is Colon Cancer Hereditary?

Familial adenomatous polyposis as a cause of colon cancer

Familial adenomatous polyposis is a hereditary disease.
As part of this disease, many polyps develop in the colon at an early age. So many can form that the entire lining of the colon is lined with polyps. Because the number of polyps is so extremely high, people with FAP have an almost 100% risk of colon cancer.
Because the entire mucous membrane is covered by polyps, it is difficult to detect in a colonoscopy if a polyp has developed into an adenoma and thus a precancerous stage. For this reason, it is recommended that, after a certain age, the entire colon is removed to prevent colon cancer.

Gardner syndrome as a cause of colon cancer

Gardner syndrome is a rare hereditary disease that is associated with a greatly increased risk of various cancers.
In addition to the increased risk of soft tissue tumors and benign bone tumors, a large number of polyps form in the large intestine, such as in familial adenomatous polyposis. Colon cancer can develop from these polyps over time.

Peutz-Jeghers syndrome as a cause of colon cancer

The Peutz-Jeghers syndrome is also a rare hereditary disease.
It is characterized by pigment spots on the skin and the mucous membrane. Furthermore, the Peutz-Jeghers syndrome also leads to excessive polyp formation. The polyps arise not only in the large intestine, but also in the entire gastrointestinal tract. The polyps increase the risk of cancer.

You may also be interested in this topic: Pigment disorder- causes and treatment options

HNPCC (Lynch Syndrome) as a cause of colon cancer

Lynch syndrome is also a hereditary disease that is associated with an increased risk of various types of cancer. About 5% of all colon cancers arise in the context of Lynch syndrome. In contrast to the other syndromes, there is no excessive polyp formation in Lynch syndrome.
Other tumors that commonly occur in Lynch syndrome are cervical cancer, small bowel cancer, stomach cancer and ovarian cancer. If there are known syndromes in a family that are associated with an increased risk of colon cancer, regular and detailed colon cancer screening is essential.

Related cancers

Colon cancer usually develops in the colon. In rare cases, however, adenomas or lymphomas in the small intestine or the duodenum can also occur.
Interestingly, people who have themselves or a close relative who has developed another type of cancer, e.g. If you have ovarian, breast or cervical cancer, you have an increased risk of colon cancer.