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.
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.
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: anemia, or a low red blood cell countbleeding problems due to poorly working blood clotting cells, called plateletsloss of normal white blood cell function, which increases the risk of infectiona need for red blood cell transfusions
It is not known what causes leukemia. Bone marrow is very sensitive to damage, and some possible causes include: certain genetic defectscigarette smokingexposure to certain chemicals, such as benzene and tolueneexposure to large doses of radiationin rare cases, certain types of chemotherapy, which can lead to acute leukemiasome unusual viruses, which can lead to rare types of leukemia
Dosages of chemotherapy drugs and radiation should be limited to the minimum necessary to achieve the treatment goal for which they are given. Persons should avoid using tobacco and minimize exposure to organic chemicals such as benzene and toluene.
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 by a pathologist, can confirm that a person has leukemia.
Acute leukemia of any type can quickly lead to death if it is not treated. Chronic leukemia will eventually be fatal if 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 to kill the leukemia cells.These medicines are usually given over several months. They kill the leukemia cells. They can also severely damage the normal cells produced in the bone marrow.
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.
Some people are given bone marrow, either one's own marrow that has been banked during a remission, or from a genetically matched donor, to help recovery. This is called a bone marrow transplant. It is generally used only when ordinary chemotherapy has failed.
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: allergic reactions to medicinesbleeding problems that may require transfusionscommon or unusual infectionsdiarrhea or poor food absorptionirritation of the gastrointestinal tractmouth soresnausea and vomitingnumbness or burning pain in the extremitiesweakness and fatigueweight loss
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 usually 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, blood tests will be done regularly to make sure the person is still in remission. A bone marrow sample may also be needed periodically. Any new or worsening symptoms should be reported to the healthcare provider.
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.