What is Acute Lymphocytic Leukemia?
It is a type of cancer that originates in the white blood cells. Consequently, it involves both the blood and bone marrow, the place in the body where white blood cells get born. It is alternatively called acute lymphoblastic leukemia and is characterized by the increased production of immature lymphocytes, meaning lymphocytes that are not ready to function properly yet. The condition is acute, manifesting suddenly and is rather progressive, with the excessive production and accumulation of immature lymphocytes.
Acute Lymphocytic Leukemia classification
It may present as one of the various subtypes identified in the human organism. It is generally classified depending on the cell type more profoundly involved. Therefore, we can divide acute lymphocytic leukemias into three subtypes:
- B-cell acute lymphocytic leukemia
- T-cell acute lymphocytic leukemia
What are the risk factors for Acute Lymphocytic Leukemia?
Not everybody is prone to this cancer, but those who are, tend to verify the accuracy of some risk factors. Risk factors usually vary between environmental, lifestyle and genetic ones. Having one or more risk factors does not necessarily mean you will certainly develop the disease. Some of the most widely considered risk factors for acute leucocytic leukemia are the following:
- Exposure to benzene and/or ionizing radiation
- Tobacco smoking
- Genetic syndromes or diseases such as Down’s syndrome, Fanconi anemia, ataxia-telangiectasia, and Bloom syndrome
- History of chemotherapy
- Viral infections such as infection with HTLV-1 (human T cell leukemia virus)
- Electromagnetic fields
- Low immunity
In general, It is not considered an inherited cancer. What is widely known and agreed on, is that acute lymphocytic leukemia is the result of mutated DNA that corresponds to some of the cells and functions of the bone marrow.
A DNA mutation is an error that prevents a cell to follow its life cycle by not letting it die. This error corresponds to a different DNA sequence that leads to a mutated gene. Consequently, the mutated gene will give birth to an abnormal compound whose phenotype is, in our case, acute lymphocytic leukemia.
Early signs and symptoms of Acute Lymphocytic Leukemia
Symptoms and signs result from normal blood cell insufficiency. The sprawling behavior of the cancer cells prevents normal blood cells from functioning and proliferate accordingly. This phenomenon can be seen in blood exams but may also manifest as symptoms and signs.
Some of the most common symptoms and signs of this cancer are:
- Dizziness or lightheadedness
- Persistent or relapsing infections
- Bruises on the tegument
- Frequent bleedings
Other symptoms may be general and constitutional and although being non-specific, loss of appetite, weight loss, night sweats, and fever are some of the most common symptoms acute lymphocytic leukemia presents with. However, their generic nature should make us think of acute lymphocytic leukemia as an exclusion diagnosis.
Abdominal swelling might also be a sign of this cancer. It is the result of hepato-splenomegaly, meaning the enlargement of the liver and spleen in response to this particular type of cancer. Lymph nodes enlargement may also be noticed as lumps under the skin. Finally, this cancer can cause bone or articular pain.
In the case of metastasis, other organs might be involved and produce symptomatic phenotypes. For example, brain metastasis might lead to headaches, vomiting, seizures or balance disturbances. Likewise, chest metastasis may interfere with normal breathing.
When this cancer is of T cell subtype, symptoms and signs may involve the thymus.
The thymus is a small organ located in front of the windpipe. It is a gland associated with the immune system and most importantly with the T cells.
In the context of T cell acute lymphocytic leukemia, thymus gets enlarged and compresses the adjacent organs, such as the trachea, causing breathing difficulties. The superior vena cava (SVC) syndrome is also the result of thymus enlargement. In other words, an enlarged thymus will press on the superior vena cava, giving birth to a particular and life-threatening syndrome characterized by:
- Swelling in all the territories superior to the compression point
- Potential consciousness changes
How to prevent this cancer?
In general, you cannot prevent a condition for which the exact cause is unknown. However, one can avoid all those things considered as risk factors for acute lymphocytic leukemia.
Smoking cessation is an important step in preventing not only this cancer but a variety of cancer types. Avoiding benzene which is a widely known carcinogenic chemical will lower the risk of developing this cancer.
How to treat Acute Lymphocytic Leukemia?
Steps involved in the treatment of this cancer are as follows:
- Induction therapy, aiming to actively restore the normal blood cells balance
- Consolidation therapy, aiming to kill any remnants of cancer cells
- Maintenance therapy, aiming to prevent any relapse
Treatment usually lasts for two or three years and can be a combination of chemotherapy, targeted therapy, radiation therapy, and bone marrow transplant. The older the individual, the more difficult it gets to treat.
According to the prognosis of acute lymphocytic leukemia, some individuals chose to follow symptomatic treatments instead of therapeutic ones, when the complications of the latter seem to outweigh the benefits. In such a case, the goal of the treatment is to improve the quality of life and extend survival time.