Basic knowledge about leukocytes in colorectal cancer
If a person suffers from a so-called colorectal carcinoma , he is suffering from colon cancer . The malignant tumor is located in the intestinal tract, with the colon and rectum being affected in 95 percent of cases. The immune system reacts to the cell mutations and activates, among other things, the white blood cells, the so-called leukocytes . In colon cancer, the values are therefore usually elevated. Read what significance these values have and how leukocytes work in cancer in the intestinal area:
Why are leukocytes increased in colorectal cancer?
To understand why the leukocyte count increases in colorectal cancer, the role of these white blood cells must be considered. First, they are roughly divided into five sub-forms:
1. Lymphocytes are the most important representatives of the white blood cells and make up up to 40 percent of the total. They react to hostile processes and produce suitable antibodies as an immune response. They are not only directed against pathogens, but also against cancer cells.
2. Although monocytes only make up around five to ten percent of the total number of all leukocytes, they are irreplaceable as “scavenger cells”. Dead pathogens and malignant cells are absorbed and digested by them. It is therefore a kind of internal body waste disposal.
3. Neutrophils move around the body at high speeds, “chasing” bacteria. They make up about 40 percent of all existing leukocytes in every human being.
4. Eosinophils are also very fast and fight against parasites in the body. In addition, it is involved in allergic reactions.
5. Although basophils make up only about one percent of leukocytes, they are directly involved in inflammatory processes. They are therefore important in order to effectively combat pathogen foci.
Lymphocytes and monocytes are therefore particularly important for the immune system’s fight against cancer. Once the body’s defenses have identified a tumor, they increase the number of these leukocytes in response.
How does the doctor determine the number of leukocytes in colon cancer?
In order to be able to realistically assess the state of health of a patient with colorectal cancer, a blood count must be taken regularly. The classic blood draw via a vein in the arm is sufficient for this. The sample is then sent to the laboratory and evaluated there.
To assess the condition of the white blood cells, they are checked to see if their count is within the normal range. In an adult, this varies between 3,800 leukocytes per microliter of blood and a maximum of 10,000 leukocytes per microliter of blood. If the number is significantly higher, the doctor speaks of leukocytosis . If it is below that, it is leukopenia .
When does the leukocyte count increase or decrease in colorectal cancer?
Because the leukocytes in colorectal cancer initially become very active to kill and eliminate malignant cells, patients first present with leukocytosis . In this phase, the immune system tries to stop the cancer with all available forces.
In the long run, however, the body cannot maintain this peak performance of the immune system, and as the cancer progresses there is a switch to leukopenia. Especially when metastases have formed in the body, the immune system is often already exhausted.
Once the cancer has reached the bone marrow, the number of leukocytes also decreases. The reason: The white blood cells arise from progenitor cells that grow in the bone marrow. Through metastases in the bone marrow, the cancer can cut off the supply of leukocytes to the immune system.
Leukocytes in colorectal cancer: is a blood count sufficient for diagnosis?
Many patients who have been to the doctor for various reasons and had a blood count done there are unsure about their result if the leukocyte value was elevated. They worry if this could be a serious sign of cancer.
The most important fact about this: A blood test alone is not enough to diagnose colorectal cancer. There are a number of reasons that can lead to an increase in leukocytes. For example, it could be a harmless infection. This does not just mean colds, which you as a patient experience through classic symptoms, but also other sources of infection.
Deviating blood values are therefore primarily an indicator that the body is not in balance. Many white blood cells speak for a focus of disease, which should be identified by further examinations.
Why should the leukocytes in colorectal cancer still be checked regularly?
Even if the number of white blood cells cannot be used for a clear diagnosis, it is an important prognostic tool for patients with colorectal cancer. There are three reasons for this:
1. If the leukocyte value is still above 10,000 shortly after the cancer diagnosis, the doctor can read from this that the organism is in the resistance phase and that no metastases have yet formed in the bone marrow. This is an important statement for the further prognosis.
2. Regardless of the current stage of the tumor, the blood count shows how severely a patient is responding to the prescribed medication. Some active ingredients from the field of chemotherapy act directly on the leukocytes. In the case of colorectal cancer, the number of white blood cells can drop even without metastases forming. If an active ingredient with this known side effect is taken, the doctor must therefore clarify whether it is due to the drug or to metastasis formation.
3. If the number of leukocytes falls without the influence of medication, the oncologist can assume that metastases are forming. The therapy can be quickly adapted accordingly.
Sources and literature:
Geißler, M. & Graeven U.: Colorectal carcinoma: evidence-based guidelines, Georg Thieme Verlag, 1st edition, 2005
Dorothea Zucker-Franklin (ed.): Atlas of blood cell function and pathology. Stuttgart 1990
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Medical note for our readers:
Our patient information explains medical topics in a simple and understandable way. Our information is not a substitute for a medical examination. Please see a specialist for diagnosis or treatment.
