This type of blood cancer can have different causes and symptoms.
In this article we are going to see in more depth what leukemias are, what classification criteria there are to categorize them and we will go into more detail about some of the types of these diseases that exist.
- Related article: “The differences between cancer and carcinoma”
definition of leukemia
The word leukemia refers to a group of malignant diseases of the bone marrow . In more popular terms, this word is considered synonymous with hematological cancer, since in leukemia there is an abnormal proliferation of leukocytes, cells found in the blood.
Cancer cells in leukemia prevent the production of cells that are so important for the protection of the body: red blood cells, platelets and leukocytes. As a consequence, very serious symptoms occur, which, if not properly treated, can lead to the death of those who suffer from leukemia.
These types of cancers are especially serious, since the cancer cells are found in the bloodstream and, through it, they can travel throughout the body, affecting other parts of the body relatively quickly.
There are different types of leukemia and, therefore, there are different degrees of severity, however, among the common symptoms that can be found when diagnosed we have:
- infections
- changes in appetite
- Fever
- Fatigue
- bleeding
- Moratones
- Swollen lymph nodes
- sweating
- Trouble breathing
- Bone and joint pain
Classification Criteria
There are two criteria for classifying leukemia.
1. Depending on the severity of the disease
The types of leukemia can be classified according to their severity.
1.1. acute leukemias
Immature blood cells proliferate very quickly . These cells cannot perform their functions correctly, in addition to being so many they occupy the space that corresponds to fully developed blood cells.
This type of leukemia is the most common in children and its treatment must be carried out as soon as possible, since there is a risk that the immature cells travel to other parts of the body.
1.2. chronic leukemias
This type of leukemia occurs more slowly , progressing over months or even years.
An excessive number of white blood cells are produced which, although mature, behave abnormally. Although it can occur in any age group, chronic leukemias are more common in older people.
2. Depending on the affected cells
Another way we can classify the different types of leukemia is by knowing which cells are affected.
2.1. Myeloid leukemia
It begins with myeloid cells , that is, those cells that originate in the bone marrow: platelets, erythrocytes, and leukocytes, or white blood cells.
2.2. Lymphoid leukemia
It begins with the lymphoid cells , that is, those cells that are part of the system that is responsible for transporting the lymph.
Main types of leukemia
Next we are going to know the different types of leukemia, its causes, symptoms and characteristics.
1. Acute lymphoid leukemia
In this type of leukemia, the body produces large numbers of immature white blood cells , called lymphoblasts, which rapidly multiply and replace the healthy cells that make up the bone marrow.
As the bone marrow is the structure that helps to form blood cells, this tissue being affected prevents this type of healthy cells from forming and, therefore, damage occurs in the body.
Acute lymphoid leukemia is one of the most common in childhood, affecting children between 3 and 7 years old. Among the causes behind the appearance of this type of leukemia are genetic factors, receiving high doses of radiation, receiving an affected bone marrow transplant or benzene poisoning.
Among the most common symptoms is having a greater predisposition to infections, in addition to running the risk of anemia and thrombocytopenia (decreased platelets), which can lead to bleeding.
2. Chronic lymphatic leukemia
In chronic lymphocytic leukemia, the lymphocytes are mature but unable to carry out their immune function . In addition, their cell death (apoptosis) is delayed, causing them to live longer than they should and accumulating.
Due to this, a greater number of these white blood cells can be observed in the bone marrow and also in the blood counts, making the immune system look very weak.
This type of leukemia is the most common in the adult population, with a higher incidence at older ages. It affects more men than women.
In chronic lymphatic leukemia there is an asymptomatic phase, in which the patient does not feel bad, although the proliferation of white blood cells has already begun.
Later, the symptoms of the disease begin to appear, such as swollen lymph nodes, liver and spleen, excessive sweating, fatigue, fever and some recurrent infections.
Patients may also report poor appetite because they feel full from too little food. Because of this, they lose weight very quickly and unintentionally.
It is not possible to speak of a total cure, although there is the possibility of improvement with a bone marrow transplant.
3. Acute myeloid leukemia
This leukemia is characterized by the accumulation of abnormal cells in the bone marrow , which interfere with the production of red blood cells.
The bone marrow is progressively replaced by leukemic cells, causing a decrease in the number of healthy red blood cells, platelets and leukocytes.
Its progression can be very rapid, becoming fatal in a matter of weeks if adequate treatment is not received.
The cause of this type of leukemia appears to be genetic, specifically a mutation in the GATA2 gene.
Among the symptoms of acute myeloid leukemia are shortness of breath, fatigue, bruising, coagulation difficulties and a greater predisposition to infections.
This disease is potentially curable. Chemotherapy is given first, with the intention of causing the cancer cells to regress. If a donor can be found, a bone marrow transplant is performed.
4. Chronic myeloid leukemia
In this leukemia, blood precursor cells are affected . It is characterized by the proliferation of white blood cells.
It occurs more in men than in women, with a ratio of 2/1.2. The chances of suffering from this type of leukemia are greater with age, especially after 45 years of age.
The cause of chronic myeloid leukemia is unknown. No relationship has been found with the consumption of drugs or infections and this disease.
The only environmental relationship seen has been that of having received high doses of radiation such as those generated in the bombings of Hiroshima and Nagasaki or the Chernobyl nuclear accident.
However, it has been seen that in people with this type of leukemia there is a genetic translocation, specifically in the BCR/ABL genes. This causes a protein to be generated, tyrosine kinase, which alters the bone marrow, making it difficult for it to function properly.
In this disease there are three phases: chronic, accelerated and transformation to acute leukemia.
The duration of the chronic phase is about 4 to 5 years. There may be no symptoms, although they usually occur: decay, weight loss, satiety, abdominal pain, kidney failure. Between 80 and 85% of patients are diagnosed in this phase.
The next phase is the accelerated phase, which lasts between 6 and 8 months. It is not well known why the disease progresses to this phase. The patient feels fevers, has anemia and his bones ache. Infections also occur.
Finally, the phase of acute leukemia or blast crisis occurs. Nearly 80% of cases at this stage progress to acute myeloid leukemia, while 20% progress to acute lymphoid leukemia.
Other types of leukemias
There are other types of leukemia depending on their causes or other characteristics.
5. Tricoleucemia
Hairy cell leukemia is also known as hairy cell leukemia . It is considered as a subtype of chronic lymphoid leukemia.
As with many leukemias, it is not exactly known what could be the cause for hairy cell leukemia, and it seems that exposure to tobacco, ionizing radiation or chemicals is not a risk factor for developing this type disease specific.
6. T-cell prolymphocytic leukemia
In this type of leukemia, the T cells behave very aggressively , attacking the blood, bone marrow, lymph nodes, liver, spleen, and skin.
This type of leukemia is very rare, affecting mostly adults in their 30s. It represents about 2% of lymphocytic leukemias. It affects less men than women, being the proportion of 2/3.
As it is such an aggressive variety of cancer, the life expectancy of patients diagnosed with this leukemia is about 7 months after receiving the diagnosis, although there have been cases of patients who have lived about five more years.
7. Juvenile myelomonocytic leukemia
It mostly affects children under 4 years of age . Among the most common symptoms are fever, bleeding, poor weight gain, infections, rashes, strong cough.
Bibliographic references
- Harris, N.L., Jaffe, E.S., Diebold, J., et al. (1999). World Health Organization classification of neoplastic diseases of the hematopoietic and lymphoid tissues: report of the Clinical Advisory Committee meeting-Airlie House. Virginia. J. Clin. Oncol., 17 (12), 3835-3849.
- Hernandez, L.; Besses, C. and Cervantes, F. (2015). Myeloproliferative syndromes. General information for the patient. AEAL explains. Madrid.
- Kipps, T.J. Stevenson, F.K., Wu, C.J., Croce, C.M., Packham, G., Wierda, W.G., O’Brien, S., Gribben, J. y Rai, K. (2017). Chronic lymphocytic leukaemia. Nature Reviews. Disease Primers, 3, 16096.
- Lehmann , S. , Ogawa , S. , Raynaud , SD , Sanada , M. , Nannya , Y. , Ticchioni , M. , Bastard , C. , Kawamata , N. and Koeffler , HP (2008). Molecular allelokaryotyping of early-stage, untreated chronic lymphocytic leukemia. Cancer, 112(6), 1296–1305.
To the classic question “what do you do?” I always answer “basically I am a psychologist”. In fact, my academic training has revolved around the psychology of development, education and community, a field of study influenced my volunteer activities, as well as my first work experiences in personal services.
