Leukemia is a type of cancer affecting the cells that run in the blood. There are various types of leukemia, and some of them show acute symptoms appearing suddenly while others have a slow and chronic progression. Leukemia is one of the most common types of cancer in children, but it affects adults as well. It is more common in males than females and has a worldwide distribution with various risk factors that include tobacco, radiation exposure, and even some types of chemotherapy used to treat other forms of cancer. Leukemia has an important genetic predisposition, and if an identical twin has leukemia, his brother or sister would have a 20% chance of sharing the same disease.
There are various types of cells running in our blood, and we can break down leukemia in two types depending on which cell line is affected. Myeloid leukemia affects myeloblasts (the precursors of neutrophils and other white blood cells) while lymphoid leukemia affects lymphocytes, another type of white blood cell divided into T cells, B cells and natural killer cells. But leukemia does not only affect immunity. It triggers various health problems and symptoms we will cover in this article:
1. Hepatomegaly and splenomegaly
The abnormal blood cells that result from leukemia spread throughout the body using the circulatory system and reach various organs, including the spleen and the liver. The infiltration into these organs usually results in significant increases in the size of the liver (hepatomegaly) and the spleen (splenomegaly). Other common sites of infiltration are the skin and the gums, and some patients would have swollen and bleeding gums as well.
In these patients, the increase in the size of abdominal organs becomes an critical problem to address, and sometimes the spleen becomes large enough to reach the belly button and push back the stomach, reducing appetite in these patients. The reason why the spleen is one of the main sites of infiltration is that this organ has the function of clearing the blood from useless blood cells. Trying to fight off the disease, the spleen becomes larger and starts causing multiple health complaints.
2. Higher susceptibility to infections
Patients with leukemia have a higher sensitivity to infections because their main problem is directly associated with their immune system, the one in charge of clearing out pathogens and protect the organism from invaders. For example, in acute lymphoblastic anemia, patients have very low neutrophil counts, and these are the first line of defence against microbial invaders. In most cases, the severity of infections is higher as the neutrophil count goes lower. Infections will be especially prevalent when the neutrophil count is around 500/µL, and it is severe and often life-threatening when it reaches 100/µL.
Thus, an aggressive infection can be fatal in these patients, and they need extra measures to protect their digestive tube, airways and urinary tract from microorganisms. Infections are the most common causes of death in leukemia patients, so there should be continuous check-ups to treat them promptly and improve the quality of life of the patient.
3. Fever
It is one of the most common symptoms, especially in acute forms of leukemia. Sometimes, patients with acute lymphoblastic leukemia have fever with not many other symptoms and no signs of infections. Doctors investigate these patients looking for infections because fever is a sign of this type of ailment until proved otherwise, and they still do it in diagnosed patients because infections can be lethal in leukemia. Thus, if you have been diagnosed with leukemia and have a new and unusual bout of fever, it is very important to ask your doctor about your condition. Not being overconfident about fever would help doctors detect and treat infections faster before they spread and become difficult to manage.
4. Chills and night sweat
One of the most common symptoms associated with fever is chills. This is a common response the body has to the increase in temperature threshold by the brain. The command of increasing body temperature comes from the central nervous system, and when it reaches the muscle tissue, it starts burning energy with jerking movements (chills) to transform stored energy into heat.
That is the reason why patients with leukemia often wake up drenched in their own sweat. Night sweats are very uncomfortable and may result in severe sleep problems that contribute to fatigue. When leukemia patients have an infection, they are even more likely to undergo night sweats and fever. It is also a common side effect of chemotherapy.
5. Fatigue
These patients often have various physical and behavioural signs of anemia, and their blood flow carries less oxygen and nutrients than the body needs. The metabolism is altered by cancer, and these abnormal cells require excessive energy to keep surviving and dividing. This energy is obtained from the organism, and since cancer cells are aggressive and greedy compared to their normal counterparts, the patient ends up with low energy levels and severe fatigue.
In some cases, acute myeloid leukemia in children starts with fatigue and other symptoms and may be sustained for weeks or months. In other cases, they have an acute presentation and develop the complete set of symptoms in a matter of 1 or 2 weeks.
Other symptoms associated with fatigue and bone marrow failure is dizziness, difficulty to breath or physical exertion that may even lead to chest pain in patients with a heart condition. In some cases, myocardial infarction is the reason why these patients go to the doctor and after performing the appropriate tests, they are diagnosed with a form of leukemia.
6. Enlarged lymph nodes
Lymph nodes are an essential part of the immune system, and they are affected in leukemia as well. Some patients would not have enlarged lymph nodes and it is not required to make the diagnosis, but it is particularly important in lymphoblastic anemia because the lymphocytes are transported by the lymphatic system and accumulate in the interior of the lymph nodes. When T-cells are taken, patients may have a big mass in the middle of the chest that interferes with their normal breathing.
Enlarged lymph nodes are often an early manifestation of leukemia, and there are certain locations and characteristics that would be more suspicious for doctors. If you have enlarged lymph nodes, there are many other health problems to rule out, and most of them are viral infections because the lymphatic system is also behind the body defences against most types of viruses. Thus, do not assume anything and talk to your doctor about your condition.
7. Uncontrolled bleeding and thrombosis
Patients with leukemia have various types of blood clotting and healing problems, and the root cause lies in an alteration of the normal function of the bone marrow. In the bone marrow, we have the stem cells that convert into various types of blood cells. There are many structural and functional changes in the bone marrow, and the number of platelets is significantly reduced. That’s why patients usually display easy bruising and continuous bleeding with a very slow healing process.
Some patients with acute lymphoblastic leukemia would also display something called disseminated intravascular coagulation when they are diagnosed. It is an abnormal activation of the blood coagulation throughout the body that contributes to the formation of microscopic thrombi. As a result, there are no available clotting factors and platelets when there is an actual bruise, and it increases the bleeding. These patients are also more susceptible to thrombosis and similar complications. Thus, they often need to remain hospitalized for a very long time.
The most common manifestation of coagulation disorders in these patients are spotting and changes of colour in the skin, primarily located in the lower extremities. Patients may wake up with a new bruise, clinically named ecchymosis, and sometimes they have smaller spots in the skin, called petechiae.
8. Reduced appetite
Up to 20% of patients with leukemia experience early satiety and reduced appetite as a result of an increase of volume in the spleen. As it becomes bigger, the spleen fools the brain into thinking that the stomach is already full of food. It is something similar to what happens in bariatric surgery when a reduction of volume in the stomach results in lower energy intake and weight loss.
An additional reason contributing to a reduction of appetite is the role inflammatory cytokines have in the central nervous system. These and other inflammatory mediators released to the bloodstream inhibit appetite and may even result in vomiting or nausea after a large meal.
9. Weight loss
There are several reasons contributing to weight loss in leukemia. One of them is what we have already mentioned about early satiety and reduced appetite. These patients are likely to have a lower energy intake compared to the average population, and they usually have various nutrient deficiencies that should be addressed as a part of the therapy.
Additional to low appetite levels, we have described how cancer cells become aggressive and change the entire metabolism, increasing the level of energy consumption. Thus, patients undergo metabolic stress that further reduces the available nutrients and oxygen from the blood.
Unplanned weight loss is a common trait of most types of cancer, and it is usually associated with the outcomes of the patient. It is a part of cachexia, which is the clinical name of the wasting syndrome consisting of chronic fatigue, muscle weakness, muscle wasting, reduction of appetite and unplanned weight loss. It is imperative to ask your doctor if you have these symptoms, especially if you have lost 5% of your body mass or more without any change to your diet, medications or physical activity.
10. Neurologic symptoms
Patients with leukemia and neurologic symptoms are often difficult to treat because they probably have a very severe condition called leukostasis. In these patients, there is an extremely high number of immature white blood cells in the blood, and this affects the normal circulation in the brain. This extra bulk in the blood slows down the normal circulation of the blood in the smaller arteries, leading to a reduction in oxygen and nutrients to the brain tissue. Leukostasis symptoms include an altered mental status, respiratory distress, seizures, and other neurologic problems.
11. Bone pain
When there is a massive number of leukemic cells in the bone marrow, patients often experience bone pain. It is not located in a given area and might be dispersed in various parts of the body, but it can be quite severe and force patients into the emergency room multiple times.
Besides bone pain, leukemia patients often have mineralization problems, and they are more susceptible to fractures than the normal population. In some cases, patients with leukemia develop a condition called myeloma, which is a mass or tumor made of cancer cells in the bone marrow. This triggers bone pain and aggravates the condition of the patient.
Leukemia is different from many other types of cancer, but the treatment of this condition is very similar. Since leukemia affects a high number of children, treatment choices will depend on the age of the patient and their genetic predisposition. Chemotherapy is the routine treatment for a while, and most patients undergo maintenance chemotherapy. Some patients may also need tyrosine kinase inhibitors, rituximab, and other drugs to improve immune function. In some cases, stem cell transplantation is needed to provide a full recovery.
However, in all cases an early treatment is what really saves lives, and you would contribute to the early detection of leukemia by reporting abnormal signs and symptoms and performing your routine check-ups once a year or more often depending on the recommendations by your healthcare provider, and even if you feel healthy.
References
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Döhner, H., Weisdorf, D. J., & Bloomfield, C. D. (2015). Acute myeloid leukemia. New England Journal of Medicine, 373(12), 1136-1152.
Murakami, J., & Shimizu, Y. (2013). Hepatic manifestations in hematological disorders. International journal of hepatology, 2013.
Taylor, J., Xiao, W., & Abdel-Wahab, O. (2017). Diagnosis and classification of hematologic malignancies on the basis of genetics. Blood, 130(4), 410-423.