How to prevent colon cancer?

Colon cancer typically occurs at a later age. Thanks to early detection, the incidence rate among people over 50 is now falling. On the other hand, more and more younger people are becoming ill: In Germany, for example, the new illness rate among 20 to 29 year olds has more than doubled within a decade. The causes for this development are not yet known, but experts suspect that it could be due to changed lifestyles. Overweight, lack of exercise, unhealthy diet, alcohol consumption and smoking are the classic risk factors for bowel cancer. A healthy lifestyle and diet therefore help prevent bowel cancer. However, one should not rely on this alone: in any case, cancer screening tests are indispensable.

A younger age is also found in people who have a family or hereditary risk of developing bowel cancer. This is the case in about 30 percent of colorectal cancer cases. People from these groups need early, regular examinations at an early age in order to detect bowel cancer and its precancerous stages as early as possible.

Identify risk

Colorectal cancer is a tumor disease that is increasingly occurring in western countries and is on the rise. Numerous studies have shown that the development of colorectal cancer is also linked to Western diet and lifestyle habits. Its incidence increases with age. But younger people can also develop bowel cancer. In recent years, the number of people under the age of 50 with bowel cancer has even increased.

The risk of developing bowel cancer is particularly high if there is a family risk – i.e. there are cases of bowel cancer in the family. It is therefore particularly important for family members of colon cancer patients to clarify their personal risk.

About one third of all bowel cancer cases have a hereditary predisposition. If you belong to this group, regular examinations at a younger age make sense in order to detect bowel cancer and its precancerous stages as early as possible.

Risk factors

Based on many years of experience and research with colorectal cancer, different factors can now be identified that increase the risk of colorectal cancer:

  • Familial, genetic risk: People in whose families there are cases of intestinal cancer or polyps carry an increased risk. It is particularly high if the family may have a hereditary form of colon cancer. People with colorectal cancer cases in their relatives should therefore inform themselves at an early stage and participate in colorectal cancer screening at an early age. Here you can find more information about the risk of bowel cancer in families.
  • Risk factor age: With increasing age, our organism becomes more susceptible to genetic cell defects, which are no longer easily repaired by the body’s own repair systems. This increases the risk that degenerate cells develop, survive and can multiply and spread malignantly as cancer tumors. From the fifth decade of life onwards, the risk of intestinal cancer increases, and the precancerous stages can already be detected 10 to 15 years earlier during cancer screening in the intestine.
  • Risk factor inflammatory bowel disease: Long-standing, chronic inflammatory bowel diseases increase the risk of developing bowel cancer. The ongoing inflammatory process can lead to malignant cell changes in the intestinal mucosa. Read more here.
  • Risk factor diabetes mellitus type 2: Patients with type 2 diabetes have a three times higher risk of bowel cancer than the normal population. The rate of fatal disease progression is also higher in this group of people. Experts believe this is due to the growth-promoting effect of insulin, which promotes the development and proliferation of tumour cells. Read more about the risk of type 2 diabetes here.
  • Risk factor nutrition and lifestyle: The typical western diet with plenty of animal fat and relatively little cereals, fruit or vegetables favours the development of various diseases, including colon cancer. In addition, obesity, lack of exercise, smoking and alcohol consumption are other factors that increase the risk of colon cancer. Everything you need to know about nutrition and lifestyle can be found here.
  • Risk factor bowel polyp: People who have already had bowel polyps discovered and removed have a particularly high risk of developing new polyps, which over time could degenerate into bowel cancer. It is therefore important to follow the recommended post-operative check-ups after polyp removal so as not to overlook new polyps. Read more about intestinal polyps and polyp removal here.

Colon Cancer screening

The preventive program against colorectal cancer depends on the individual risk of developing the disease. This determines when and how often an examination makes sense. A distinction must be made between people with an increased risk – e.g. a family history – and those without an increased risk of colon cancer.

In principle, if there is an increased risk of bowel cancer, preventive examinations must be started at a younger age.

Examination methods for early detection

There are various examination methods available for the early detection of colon cancer. In the following, the methods of colorectal cancer screening are briefly presented (more information on the individual examinations can be found here).

Test for hidden blood in stool (immunological stool test): This test can be used to detect hidden blood in stool that cannot be seen with the naked eye. Such traces of blood from the inside of the bowel can come from bowel polyps (possible precursors of bowel cancer) or even from bowel cancer. The occult blood test should be carried out regularly, i.e. once a year. If the test is positive, the result should be clarified by a colonoscopy. Although not every positive blood test in the stool means bowel cancer, only a colonoscopy can really provide certainty.

Palpation of the rectum: A relatively simple method that the family doctor can perform. The doctor palpates the lower part of the rectum with his finger. About a quarter of the tumours in the rectum are thus detected. However, intestinal tumours or polyps often also occur in higher intestinal sections, so that the palpation examination alone is not sufficient to prevent intestinal cancer.

Colonoscopy: Currently the most effective and accurate method for the early detection of colorectal cancer. Colonoscopy is almost 100% effective in preventing bowel cancer. Used regularly, almost all polyps can be found and removed. In addition, malignant bowel tumours are often discovered at an early stage when they are still curable. Before the colonoscopy, the intestine must be emptied and cleaned by laxative measures. During the colonoscopy, the doctor inserts a thin, tubular examination device (endoscope) through the anus into the intestine. A mini camera is mounted at the tip of the device, which can be used to inspect the inside of the intestine precisely. Special working channels in the endoscope allow small instruments to be inserted into the intestine, with which tissue samples can be taken or intestinal polyps removed from the intestine.

Virtual colonoscopy (CT colonography): As a high-tech procedure, virtual colonoscopy enables an “external colonoscopy”. Computer tomography (CT) or (rather rarely) magnetic resonance tomography (MRT) is used to create layer images of the abdominal cavity, which are converted into a spatial image of the intestine with the aid of a 3D computer program. The doctor can now search the intestine for suspicious areas on the screen. The advantage of this method is that no examination instrument has to be inserted into the intestine. But also here a preparatory intestinal cleaning is necessary. Virtual colonoscopy is less accurate than colonoscopy: small or flat intestinal polyps can be overlooked. If a polyp is discovered, a normal colonoscopy must follow in order to be able to remove the polyp with the help of the endoscope.

Polyp removal (polypectomy)

Bowel polyps can degenerate into cancer. Although not all polyps develop into malignant tumours, polyps that have been discovered are removed for safety reasons. This usually takes place during a colonoscopy, in which the doctor guides forceps or loop instruments through the working channel of the endoscope and thus separates the polyp from the intestinal wall. The tissue of the ablated polyps is then examined in the laboratory to determine the type and characteristics of the polyps and whether cancer cells have possibly already formed in a polyp.

The big advantage of this method is that the colonoscopy with polypectomy is able to carry out diagnosis and therapy in a single step. The timely removal of intestinal polyps can prevent many intestinal cancers. Read more about polyp removal here.

Prevention for people without increased risk

For all those who have neither a family burden nor an increased risk due to a chronic inflammatory bowel disease, it is recommended to go to bowel cancer screening from the age of 50. This is because the risk of age-related bowel cancer increases from the age of 50.

From the age of 50, the statutory health insurance funds cover the costs of the annual stool test for hidden blood as well as the rectum palpation. From the age of 50 for men and 55 for women, a colonoscopy is paid for by the health insurance companies as a precaution. If no abnormal findings are found, a colonoscopy can be performed again after 10 years. Since 1 July 2019, all insured persons who have reached the age of 50 have been invited by their health insurance company to undergo colon cancer screening. Unless the insured do not object, further invitations will be issued at the age of 55, 60 and 65.

Preventive programme for risk groups

For people at risk of familial colorectal cancer, screening must be started earlier than for people without a hereditary risk or with colorectal cancer in the family. If you suspect hereditary colorectal cancer (HNPCC or FAP, you can find more information here), you should seek advice from a human genetic counselling centre on how to proceed and encourage your family to make use of this offer. If the analysis of the family tree leads to the suspicion of HNPCC or FAP, molecular genetic tests can be used to attempt to detect characteristic changes in the genes in the blood cells of individual family members. However, not all members of the family are carriers of the altered genetic material. However, those in whom a typical genetic alteration is detected should undergo intensified screening for hereditary colorectal cancer. In familial adenomatous polyposis (FAP), precautionary measures start at the age of 10, in HNPCC at the age of 25.

For familial colorectal cancer, in which the genes involved are not yet known, there are still no effective test procedures that could prove hereditary strain. Nevertheless, people from such families also belong to the group of high-risk patients and should be integrated into a special prevention programme. The first preventive colonoscopy should be 10 years before the age at which colon cancer first appeared in a sick family member. However, this often does not take into account illnesses that are not known in the family, such as grandparents who died of an undefined cancer in the abdominal cavity. Young people from families with suspected family history of colorectal cancer should therefore undergo their first preventive colonoscopy at the age of 40-45 at the latest.

For patients with chronic inflammatory bowel diseases such as ulcerative colitis, another risk group, special screening programmes also apply. For all people with an increased risk of bowel cancer – whether hereditary, familial or due to inflammatory bowel disease – the necessary preventive measures are covered by health insurance, regardless of age. Read more about the important bowel cancer screening programmes here.