Malignant intestinal tumors occupy an inglorious leading position in industrialized countries: in cancer, they rank second in men and women. Almost 70, 000 people are diagnosed each year, and one in four is still succumbing to this condition. Almost all malignant neoplasms emanate from the glandular tissue of the large intestinal mucosa (adenocarcinoma), cancer in the small intestine is very rare.
Where exactly does the cancer originate?
Colon cancer is by far the most common colorectal cancer - cancer of the colon (colon carcinoma) and / or rectum (rectal carcinoma). Because not only the large intestine (colon), but also the appendix with its appendix belongs to the large intestine, on the other hand the rectum (rectum) to the anus is again an independent section behind the large intestine, the common names are colon cancer or intestinal cancer actually inaccurate.
How does colon cancer develop?
The vast majority of carcinomas result from benign mucosal growths (adenomas, polyps). The degeneration probability depends on the histological structure and on the size (from one centimeter) of the benign growth.
By increasing mutations, the cells differ so much from the original structure that they develop an unregulated and uncontrolled growth. They lose contact with other intestinal cells, leave the cell structure and penetrate the surrounding tissue. If they reach the blood or lymphatic channels, they can be trafficked throughout the body and form metastases. Most commonly degenerated tissue is formed in the rectum (rectum). The further you go up the colon, the rarer it is.
In the further course of the disease, offshoots, especially in the liver and in the case of deep localization of the carcinoma (in the lower rectum), can also develop in the lungs. From these organs, further scattering can take place throughout the organism. People who tend to form colon polyps because of their genetic makeup are at particular risk of developing colon cancer. Thus, certain genetic diseases exist (familial adenomatous polyposis = FAP), which, if left untreated, lead to colon cancer.
In addition, diet-related influences are known: Meat and high-fat, low-fiber diets and obesity are major risk factors. They cause the stool to stay in the intestine for a longer time, prolonging the contact time with the mucous membrane. This irritates the intestinal mucosa causes more toxins enter the intestinal cells - and thus increases the likelihood that they multiply uncontrollably.
In addition, cigarette smoking - as with almost all cancers - also promotes malignant proliferation. Certain operations in the colon (for example, the connection of the ureters with the large intestine) or chronic inflammation of the digestive organs (ulcerative colitis) are also associated with an increased risk of cancer.
Frequency of colon cancer
Colorectal cancer is a common disease in our latitudes and is on the increase. Over the course of a few decades, colorectal carcinoma has advanced to become the second most common cancer in men and women. 90 percent of people over the age of 50 are affected - women and men approximately equally. For the normal population, the statistical risk of developing colorectal cancer is around 6%, and for risk groups (eg hereditary susceptibility), it is sometimes much higher.
A major reason for the increase and discrepancy to other regions of the world (for example Africa) is on the one hand the increasing life expectancy and on the other hand the prosperity in the western world. A much too high in food and calorie intake, combined with a high proportion of animal fats and low fiber content is just as common with us as sedentary lifestyle and obesity.