Why do white blood cells decrease in cancer patients undergoing chemotherapy?

White blood cells have a role in fighting infections caused by bacteria, viruses, fungi and other pathogens that enter the body. When a person is undergoing chemotherapy for cancer, the side effects of leukopenia are quite common. This will make it harder for the body to fight off pathogens and the patient will be more likely to get infections, which will interfere with cancer treatment regimens.

White blood cells are one of the types of blood cells, responsible for protecting the body against infection. There are many different types of white blood cells, which are involved in different stages in the whole process of cellular and humoral immunity. Accordingly, when the body has an attack of bacteria, viruses, fungi and other pathogens from the environment entering, white blood cells will quickly gather at the infection site and create a defensive barrier. kill pathogens and avoid spreading. At this time, the basic test to check white blood cell counts and components is a complete blood count.
For patients undergoing chemotherapy for cancer, leukopenia is a common side effect. Sometimes, this is also an obstacle in the treatment process for the patient, making the benefits of treatment and the possible risks need to be carefully weighed, because it can be life-threatening.
Causes of the link between cancer chemotherapy and a decrease in white blood cell count include:
Drug effects: Chemotherapy drugs are injected into the body to destroy cancer cells. However, if the selection of abnormal cells is nonspecific, leukocytes may also become subject to destruction. Therefore, not only leukopenia, the patient may also have a decrease in the number of other blood cells such as red blood cells and platelets.

Bone marrow damage: Because chemotherapy is a systemic cancer treatment, it has systemic effects that can affect all organs in the body, so bone marrow can also be avoided. The spongy bone tissue in the bone marrow is the place to produce blood cells in general, and white blood cells in particular. Therefore, when the bone marrow is damaged, the number of white blood cells is also reduced. Intervention to extract blood and destroy bone marrow. For people with blood and bone marrow cancers, such as leukemias, which cause uncontrolled growth in the bone marrow, massive white blood cell counts and compression of other blood cell lines, Before chemotherapy intervention and to increase the effectiveness of the drug, the patient may be considered for intervention of blood extraction and bone marrow destruction. In the meantime, complications of leukopenia are completely unavoidable. Cancer Metastasis: When cancer cells break off from a tumor in any organ, enter the bloodstream or lymphatics, they can spread to other parts of the body, including the marrow. skeletal. There, cancer cells can replace the blood-forming cells in the bone marrow, making it harder for the bone marrow to continue producing the blood cells the body needs. This is a cause of abnormal blood cell counts in general, white blood cells in particular.

When a person has a low white blood cell count there is an increased risk of infection. Furthermore, in subjects undergoing chemotherapy for cancer, this level of risk is significantly increased, depending on several factors as follows:
How much white blood cell count is reduced Condition how long the white blood cell count has been going on White blood cell formula currently available Indications need to be treated with other combination drugs such as steroids or immunosuppressants Where a measure of the degree of risk has been devised is will be based on an absolute neutrophil count (ANC). The ANC is calculated by multiplying the total white blood cell count by the percentage of neutrophils:
ANC = Total white blood cell count x % neutrophils At this point, the risk of infection will be estimated based on the white blood cell count. Absolute neutropenia (ANC) is as follows: ANC greater than 1500: No increased risk of infection ANC from 1000-1500: Slightly increased risk of infection ANC 500-1000: Moderate increased risk of infection ANC from 100 -500: High risk of infection ANC less than 100: Very high risk of infection

If there is a low white blood cell count and an increased risk of infection according to the above ANC calculation formula, the patient should actively follow the following steps to avoid infection:
Wash hands frequently under running water and soap room. Avoid crowded places, especially during cold and flu season. Respiratory viruses or germs can be spread easily through coughing and sneezing. When going out, wear a mask and eye protection. Watch out for gastrointestinal infections caused by consuming contaminated food. If you have a weak immune system, especially when you are suffering from leukopenia due to cancer chemotherapy, you will be at a very high risk of gastrointestinal infections caused by Listeria, E. coli and Salmonella bacteria, as well as toxicity. Shiga element. All of these bacteria are present in contaminated, undercooked foods. Therefore, patients need to be careful from the process of cleaning, preparing and storing food combined with consuming a healthy diet that is both safe and can help you provide enough nutrients. nutrients needed to fight infection. Avoid swimming in natural rivers, lakes, ponds and streams. Cryptosporidium is a microscopic parasite and one of the most common causes of waterborne diseases. If the patient is immunocompromised due to a decreased white blood cell count, the patient is at high risk of disease from Cryptosporidium and the disease may also progress to a more severe degree than in the general population. Prevent insect bites: Insects from nature or even indoors such as mosquitoes can still carry many pathogens. These acquired infectious diseases can be very simple for the average person but can be very serious for the immunocompromised. Therefore, the sick person should avoid going out of the house before dawn or after sunset; when needing to go, must wear a hat, long-sleeved shirt and long pants; Windows and doors need to have curtains or small mesh screens and make sure there are no holes.

Limit the use of sharp objects such as cutlery to prevent cuts and scratches. Wear gloves when gardening, be careful when cutting fingernails and toenails to avoid causing skin wounds. Absolutely do not arbitrarily peel off the skin or squeeze the boil, which can lead to a very serious infection that is difficult to control. Do not perform dental procedures, cosmetic interventions or invasive procedures that may cause unnecessary bleeding while the white blood cell count is not guaranteed. If there are signs of suspected bacterial infection such as fever, cough with sputum, loose stools, purulent skin wounds..., the patient should be hospitalized immediately to be isolated and quickly use antibiotics to control the infection. , combined with other measures to increase white blood cell count such as leukocyte transfusion, leukocyte-stimulating drugs.
In summary, leukopenia is one of the common limitations in cancer chemotherapy. However, if the patient understands and strictly follows the infection prevention measures in the first place, the condition can still be well managed, helping the patient get through chemotherapy safely and high efficiency.
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Reference source: chemocare.com