Introduction
Colorectal cancer is one of the most common malignant neoplasias (new formation of body tissue) of the gastrointestinal tract. Approximately 30-35 out of 100,000 people in Germany are diagnosed with colon carcinoma, i.e. cancer of the colon. The peak age is around the age of 65.
In order to understand the effects and symptoms of colon cancer, the function of the colon will be briefly discussed here: On the one hand, the colon removes water from the food pulp, on the other hand it absorbs electrolytes and nutrients. Especially in the early stages, colon cancer unfortunately proceeds relatively asymptomatically, i.e. it is hardly noticeable. It is only in the final stages that the first symptoms, which may indicate colon cancer, appear.
These include the “B symptoms“, which are very common in clinical routine. B symptoms are when the patient has lost weight unintentionally within the last few weeks, suffers more frequently from fever attacks and experiences severe sweating, especially at night. These go so far that the complete bed linen is sweated through and has to be changed.
A positive B-symptom is an indication of a neoplastic event, i.e. cancer. In the final stage of colon cancer, other symptoms also occur. These primarily affect the function of the colon: since the colon can no longer extract water from the food pulp, diarrhea and increased water loss occur.
However, proliferations in the lumen of the colon can also lead to constipation and, as a result, to abdominal cramps. The stool habits therefore change noticeably due to the malignant (malignant) processes in the colon. The aforementioned growths in the colon lumen can also ulcerate (become ulcerous) and cause bleeding.
The blood is then added to the stool, so that after going to the toilet red blood deposits are often visible on the stool. However, red blood deposits do not automatically indicate colon cancer, and can also have a number of other causes, such as hemorrhoids or anal fissures. In fact, they are relatively common symptoms, and often have a rather harmless cause.
Due to the loss of blood, there can also be a performance kink and anemia. This is characterized by paleness, listlessness, and rapid “getting out of breath” during strenuous activities. Since the red blood cells in the blood are the carriers of the oxygen molecules, a lack of blood results in a simultaneous lack of oxygen in the body.
This can still be compensated to a certain extent, but is more noticeable during physical activity than usual. Classic symptoms are then also tachycardia and circulatory problems. Since colon cancer also forms liver metastases in the final stages, liver failure and jaundice (icterus) can occur.
The liver can no longer detoxify the body as usual, i.e. it cannot filter the blood properly. The liver‘s remodelling processes cause the bile ducts to be blocked, resulting in a backlog of bile. These two processes cause the bile pigment bilirubin to accumulate from the blood into the body tissue – the body turns yellowish.
In the final stage of colon cancer, other symptoms, such as deterioration of the general condition, occur. Since the tumor consumes a lot of energy on the one hand, but does not perform any function on the other hand, and also prevents other organs such as the colon and liver from doing their job, a drastically increased energy requirement is the result. Affected patients often feel less hungry, on the one hand because food intake can lead to abdominal cramps (see above), on the other hand because the body as a whole slowly breaks down. In some countries, stool tests are carried out for the early detection of colorectal cancer, which examine the stool for occult – i.e. not visible with the eyes – bleeding. This is currently the only possibility for early detection of colorectal cancer.
