What are the Different Types of Leukemia?
Leukemia is a type of cancer. The body part that is particularly affected by this disease is the blood cells. The signs and symptoms of leukemia are presented differently in each individual patient. It requires extensive experience to properly diagnose leukemia and to identify which stage it is in.
The symptoms of leukemia are common to all the types of leukemia, but also depend on the type of leukemia the patient is affected with. However, most of the symptoms of leukemia are non-specific. The type of leukemia an individual would develop also depends on the risk factors and the root cause of abnormal growth of the cells.
The most common risk factors in adults are:
- Male, aged 60 years or older
- Exposure to benzene or harmful radiation
- A undiagnosed or diagnosed blood disorder
- Genetic and hereditary predisposition in the family
- History of chemotherapy or radiotherapy
- Excessive smoking and alcoholism
The risk factors in children are:
- History of chemotherapy or radiotherapy
- Weakened immune system
- Family history
- History of aplastic anemia or myelodysplastic syndrome
- Genetic or congenital disorders
- Exposure to harmful rays, smoke from the cigarette, alcohol through the mother (gestational)
Classifying leukemia
There are different sub types of this malignancy, and just like in other disease conditions leukemia can be classified as:
- Acute - This leukemia occurs fast. Primarily, the affected cells are baby cells or blast cells. Basically these cells are not matured, but are growing and multiplying rapidly. If the problem is not addressed quickly, the patient can have a bad prognosis.
- Chronic - This leukemia grows and spreads slowly over a prolonged period of time since the affected cells are the more mature ones. The cells in this type of leukemia do not reach their peak maturation. This type of leukemia is reported to be harder to cure, therefore more dangerous.
Another way to classify leukemia or cancer of the blood is:
- Adult - This leukemia is present in a fully developed person; common in people 55 years and beyond.
- Childhood - This leukemia is present in children; most common in 15 years and younger.
Categorizing leukemia by cancerous cells
Typically, leukemia is also classified according to the type of cells that have been affected by cancer. Be aware that the signs and symptoms of different types of leukemia are generally alike, as all of the types affect blood cells.
There are four main types of leukemia, based on whether they are acute or chronic, and myeloid or lymphocytic:
- Acute myeloid (or myelogenous) leukemia (AML)
- Chronic myeloid (or myelogenous) leukemia (CML)
- Acute lymphocytic (or lymphoblastic) leukemia (ALL)
- Chronic lymphocytic leukemia (CLL)
The primary difference between all the main types of leukemia is based on the rate of progression and where the cancerous growth has developed in the body. The cells of acute leukemia replicate before the immune functions have developed against them, and the cancerous cells form at a much faster rate. Whereas, the cells of chronic leukemia do not replicate and mature as fast as the acute cells. Since the immune system is extremely impaired, the body is incapable of defending infections and has impaired functions of lymphocytes.
Lymphoblastic or Lymphocytic or Lymphoid
The main cells that are affected in this kind of malignancy would be the white blood cells, hence the names lymphoblastic, lymphocytic and lymphoid. You can then expect that fighting off infection would be the main problem for this type, as that is the ultimate task of our white blood cells.
The proliferated white blood cells (mostly B Lymphatic cells) combine and stay in bone marrow. Physiologically, bear in mind that B cells are the ones responsible in creating antibodies that directly fight off antigens like germs and other foreign bodies. T cells, on the other hand, act as the identifier for the group. They regulate immune response pinpointing which cells are abnormal.
They affect healthy cells, consequently preventing their proper maturation. As they increase in number, the blood stream would then carry these leukemia cells to the entire body affecting major organs such as the liver, lymph nodes and brain. As they stagnate in one place, they continue to divide and spread resulting to numerous abnormalities.
- ALL - This is Acute Lymphocytic Leukemia. This type affects mostly children, from infants to teens aged 15. Though it is very rare, it can also be seen in adults beyond 45 years old. The progression of acute lymphocytic leukemia unlike CLL can happen very fast.
- CLL - This is Chronic Lymphocytic Leukemia. As you can guess from the term "chronic", this disease progresses for years. Severe symptoms then manifest after a long period of time. Its slow development gives its distinct characterization from ALL.
Myeloid or Myelogenous or Myeloblastic
When blood-forming cells other than white blood cells are affected, it gives rise to this type of leukemia. Red blood cells (erythrocytes), platelets (thrombocytes) and other white blood cells than leukocytes are the ones causing abnormalities. This can include granulocytes, which contain granules with enzymes that destroy bacteria and viruses. Basophils, eosinophils and neutrophils are all types of granulocytes. In the same light, other white blood cells such as monocytes, the ones responsible for digesting germs and helping lymphocytes complete their mission, can turn to leukemic cells.
- AML - This is Acute Myeloid Leukemia. Abnormalities in other blood-forming cells and white blood cells (except lymphocytes) occur while the cells are still immature. This disease progresses quickly and the patient can die in a few months if he or she does not receive treatment.
- CML - This is Chronic Myeloid Leukemia. This is the type that is more common in adults than children. Unlike, AML, the advancement of this disease condition is sluggish, therefore the patient can have better prognosis.
Treatment
Fortunately, there are so many treatment options for patients with cancer of the blood these days. Thanks to continued research programs and facilities, traditional remedies such as surgery, chemotherapy and radiation therapy are being enhanced on a regular basis. The development of modern cures such as stem cell therapies, targeted cell therapies and even biological therapies are opening doors for more options. People who cannot tolerate the powerful consequences of chemotherapy can now be treated without experiencing uncomfortable side effects.
