Leukemia is a cancer that affects white blood cells. There are many types of leukemia. Each one is named for the kind of white blood cell it affects. These include myelocytes, lymphocytes, plasma cells, and other types of white blood cells.
Leukemia can be acute or chronic. Acute leukemia is a very aggressive leukemia that worsens over a brief period. Two examples of acute leukemia are as follows:
Chronic leukemia refers to a leukemia that has a slower course over a much longer period, sometimes years. Two examples of chronic leukemia are as follows:
Certain types of chronic leukemia may eventually develop into a form of acute leukemia.
When the cancerous cells grow in the bone marrow, normal bloods cells are often destroyed or crowded out. Having fewer normal white cells can cause the person to become infected easily. The infections may be serious and life-threatening. Having fewer platelets means that the person may bruise or bleed easily. Anemia, or low numbers of red blood cells, can make the person weak and easily tired.
Eventually, some of the cancerous white cells may leave the bone marrow and enter the bloodstream. They spread through the bloodstream to other parts of the body. This process is known as metastasis.
It is not known what causes leukemia. Bone marrow is very sensitive to damage, and some possible causes include:
As the cancer grows, the bone marrow will become less able to make blood components. Symptoms may develop as the bone marrow fails to make these components. The symptoms will develop more quickly in a person with acute leukemia. Symptoms of chronic leukemia may develop more slowly. Some common symptoms include:
Diagnosis of leukemia begins with a medical history and physical exam. A blood sample will be examined to see if it contains cancerous white cells. Special studies are done on these cells to determine the specific type of leukemia. A bone marrow biopsy, in which a small piece of the bone marrow is removed for examination, can confirm that a person has leukemia.
In most cases, nothing can be done to prevent leukemia. Exposure to chemotherapy and radiation should be limited, when possible. Chemicals, such as benzene and toluene, should also be avoided. Someone who smokes should quit smoking.
Acute leukemia of any type can quickly lead to death if it is not treated. Chronic leukemia will eventually cause death if it is not treated. However, the course of chronic leukemia may be many months or years. If the treatment is effective, the person may recover and live a normal life.
There are no risks to others. No one can acquire leukemia from contact with a person who has the disease.
The treatment of acute leukemia involves intensive chemotherapy. A combination of powerful medicines is given to the person through the veins. These medicines are usually given over several months. They kill the leukemia cells. They also severely damage the normal cells produced in the bone marrow.
Some people are given bone marrow from another person to help recovery. This is called a bone marrow transplant. It is used only in certain cases.
The first course of therapy is called induction therapy. It is designed to induce a remission or complete destruction of the leukemia. The next treatments are called maintenance therapy. These are designed to make the remission last by destroying any remaining disease.
Chronic leukemia is generally treated with less intense treatments. Chemotherapy is used for most types of chronic leukemia. Biological response modifiers, or BRMs, may be used for some types of chronic leukemia. BRMs are elements of the body's immune system that are combined with medicines to fight cancer.
Side effects of treatments can include some of the same signs and symptoms as the leukemia, such as:
The person will have other side effects related to the type of medicine used. Biological response modifiers cause flu-like symptoms. Nausea is common. Hair loss, or alopecia, is another side effect of chemotherapy. Medicines will be given to control these symptoms.
After therapy has been completed, the person will regain normal bone marrow function over several weeks. Treatment followed by recovery may be repeated several times until all signs of leukemia are gone.
Frequent blood tests will be taken to monitor treatment and recovery. Additional bone marrow biopsy samples will be taken to confirm that the leukemia has been successfully treated. After all therapy has been completed, occasional blood tests will be done to make sure the person is still in remission. A bone marrow sample may also be needed from time to time. Any new or worsening symptoms should be reported to the healthcare provider.
Author:Miriam P. Rogers, EdD, RN, AOCN, CNS
Date Written:
Editor:Ballenberg, Sally, BS
Edit Date:08/31/01
Reviewer:Adam Brochert, MD
Date Reviewed:08/06/01
Khouri, I, Sanchez, F.G., Deisseroth, A.(1997). Leukemias in Cancer: Principles and Practice of Oncology. 5th Edition DeVita, V.T. (ed). J.B. Lippincott: Philadelphia. Pp. 2287-2321.