Leukemia
From ChildWiki.com
Leukemia is a blood disease characterized by accumulating uncontrollably, inside the bones, the cells that are the origin of white blood cells, called hematopoietic cells. These young cells , are immature and invade the center of the bones, stopping normal blood cells from being developed.
From the young cell state and until the mature cell evolution is reached, a series of biological events are produced, which are called in their totality as being the genesis of blood cells.
Even if leukemia is considered to be a children's disease, it can affect persons of any age. The incidence of leukemia is 10 times bigger in adults than children. In fact, between 60% and 70% of leukemia cases are triggered after age 50. Almost 85% of infant and toddler leukemia are acute leukemia.
Leukemia treatment is complex and it depends on age, health, the type of leukemia and the state of evolution of the disease. The prognosis of leukemia varies a lot from one form to the other. The survival rate has risen amazingly during the last decades because the modern methods of leukemia diagnose and treatment. In 1960, only 14% of those diagnosed would survive 5 years after the leukemia diagnose. Now, that percent is close to 50.
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[edit] Leukemia Causes
In the majority of cases, the exact cause of leukemia remains unknown.
However, there have been identified certain factors that can favor, under certain circumstances, the appearance of a leukemia type:
- Massive exposure to ionic radiations
- Anomalies in genes' functions
- A prolonged exposure to chemical substances
- In rare cases, certain viruses
- Anterior treatments with anti-cancer medication
Much alike like cancer, leukemia will have just one cause in exceptional cases.
[edit] Types of Leukemia
Leukemia can be classified depending on two criteria:
[edit] Evolution
- Chronic Leukemia - is characterized by the long clinical evolution ( a couple of years), in which the immature white blood cells are retained by at the same time other white blood cells will mature. Depending on the type of affected blood cells, we have chronic lymphocytic leukemia (CLL) and chronic myelogenous leukemia (granulocytic)(CML).
- Acute Leukemia - It is characterized by a rapid clinical evolution, associated with the blocked cells (immature cells) that are deposited in the bone narrow or in the blood. White blood cells stop maturing. Depending on the type of affected blood cells, we have acute lymphocytic leukemia (lymphoblastic) (ALL) and acute myelogenous leukemia (granulocytic)(AML).
[edit] Type of Cells Affected
Depending of the types of cells affected, leukemia can be either lymphoblastic or granulocytic. The first type of leukemia is called either lymphocytic or myelogenous.
According to these four important criteria, leukemia has four different types:
- Acute lymphocytic leukemia (lymphoblastic) (ALL) - It can affect both children and adults, but it is much more frequent with children. It is responsible for 65% of kids leukemia.
- Chronic lymphocytic leukemia (CLL) - It is found especially in adults and it is twice as frequent as CML
- Acute myelogenous leukemia (granulocytic)(AML) - It is the most frequent form of acute leukemia in adults.
- chronic myelogenous leukemia (granulocytic)(CML) - Also, a leukemia form specific to adults. Patients show no symptoms for a few months or even years, until they enter a phase of the disease in which the cells are spread rapidly.
Other less encountered types are type T leukemia, and hair cell leukemia.
[edit] Signs and Symptoms
The signs and symptoms of leukemia depend on the type of leukemia and the cause. Some symptoms are caused by the deficiency of normal blood cells. The leukemia cells can be collected in different parts of the body: testicles, brain, glands, liver, lungs and so on.
The following symptoms are common to all types of leukemia:
- Inexplicable fever or chills
- Frequent infections
- Night sweats
- lack of appetite or sudden weight loss
- Persistent tiredness, weakness
- Spontaneous echimosas
When the leukemia cells are collected in different regions of the body, they can cause the following symptoms:
- Confusion
- Balance disorders
- Vision disorders
- The swelling of ganglions, liver and spline inflammation
- Breathing difficulties after a sustained effort
- Abdominal pain
- Bone discomfort or articular pain
- Weakness of loss of muscular control
- Small skin lesions
The symptoms of leukemia are not specific. They are common to a great number of diseases and affections. The severity of leukemia signs and symptoms depends on the number of the abnormal cells and on their location. The first symptoms are generally neglected, because they are much alike to those of a flu or other common disease.
[edit] Risk Factors
- As in all types of cancer, smoking is considered to be a risk factor for leukemia, even if many leukemia patients never smoked.
- Exposure to chemicals for a long time, usually at work, is considered to be a risk factor, but it is responsible for a small number of cases.
- Exposure to radiations is another risk factor. The dosage of radiations used for diagnose tests as echographies during pregnancies or the radiography to diagnose pneumonia in children and adults do not have the length or intensity to cause leukemia.
Other less frequent risk factors for leukemia are:
- Anterior chemotherapy sessions
- An infection with the human leukemia virus with T cells, type 1 (HTLV -1)
- Chromosomal disorders as Down Syndrome
- A positive familial history of chronic leukemia
[edit] Evolution
The evolution of leukemia, especially of acute leukemia, has been transformed during the last three decades, registering a remarkable decrease when it come to mortality rate, especially in case of children acute leukemia, which are usually cured in about 80% of cases. Still, these progresses are registered after difficult and aggressive leukemia treatment.
