Chronic myelogenous leukemia (also called CML or chronic granulocytic leukemia) is a disease in which too many white blood cells are made in the bone marrow. The bone marrow is the spongy tissue inside the large bones in the body. The bone marrow makes:
Normally, bone marrow cells called blasts develop (mature) into several different types of blood cells. These cells have specific jobs to do in the body. CML affects the blasts that are developing into white blood cells called granulocytes. The blasts do not mature and become too numerous. These immature blast cells are then found in the blood and the bone marrow.
In most people with CML, the genetic material (chromosomes) in the leukemia cells have a feature that is not normal called a Philadelphia chromosome. This chromosome usually doesn't go away, even after treatment. Leukemia can be acute (progressing quickly with many immature blasts) or chronic (progressing slowly with more mature-looking cancer cells). Chronic myelogenous leukemia progresses slowly and usually occurs in people who are middle-aged or older, although it also can occur in children.
In the first stages of CML, most people don't have any symptoms of cancer. A doctor should be seen if any of the following symptoms appear:
Also, the spleen (the organ in the upper abdomen that makes other types of white blood cells and filters old blood cells from the blood) may be swollen. If there are symptoms, a doctor may order blood tests to count the number of each of the different kinds of blood cells. If the results of the blood test are not normal, the doctor may order more blood tests.
A bone marrow biopsy also may be done. During this test, a needle is inserted into a bone and a small amount of bone marrow is taken out and looked at under the microscope. The doctor can then tell what kind of leukemia the patient has and plan the best treatment.
Once chronic myelogenous leukemia (CML) has been found (diagnosed), more tests may be done to find out if leukemia cells have spread into other parts of the body such as the brain. This is called staging. CML progresses through different phases and these phases are the stages used to plan treatment. The following stages are used for chronic myelogenous leukemia:
Chronic phase
There are few blast cells in the blood and bone marrow and
there may be no symptoms of leukemia. This phase may last from
several months to several years.
Accelerated phase
There are more blast cells in the blood and bone marrow, and
fewer normal cells.
Blastic phase
More than 30% of the cells in the blood or bone marrow are
blast cells. The blast phase of CML is sometimes called "blast
crisis." Sometimes blast cells will form tumors outside of the bone
marrow in places such as the bone or lymph nodes. Lymph nodes are
small bean-shaped structures that are found throughout the body.
They produce and store infection-fighting cells.
Refractory
Leukemia cells do not decrease even though treatment is given.
How chronic myelogenous leukemia is treated There are treatments for all patients with chronic myelogenous leukemia. Three kinds of treatment are used: chemotherapy (using drugs to kill cancer cells) radiation therapy (using high-dose x-rays or other high-energy rays to kill cancer cells) bone marrow transplantation (killing the bone marrow and replacing it with healthy marrow). The use of biological therapy (using the body's immune system to fight cancer) is being tested in clinical trials. Surgery may be used in certain cases to relieve symptoms.
Chemotherapy
Chemotherapy uses drugs to kill cancer cells. Chemotherapy may be taken by pill, or it may be put into the body by a needle in the vein or muscle. Chemotherapy is called a systemic treatment because the drug enters the bloodstream, travels through the body, and can kill cancer cells throughout the body. Chemotherapy also can be put directly into the fluid around the brain and spinal cord through a tube inserted into the brain or back. This is called intrathecal chemotherapy.
Radiation therapy
Radiation therapy uses x-rays or other high-energy rays to kill cancer cells and shrink tumors. Radiation for CML usually comes from a machine outside the body (external radiation therapy) and is sometimes used to relieve symptoms or as part of therapy given before a bone marrow transplant.
Bone marrow transplantation
Bone marrow transplantation is used to replace the patient's bone marrow with healthy bone marrow. First, all of the bone marrow in the body is destroyed with high doses of chemotherapy with or without radiation therapy. Healthy marrow is then taken from another person (a donor) whose tissue is the same as or almost the same as the patient's. The donor may be a twin (the best match), a brother or sister, or another person not related. The healthy marrow from the donor is given to the patient through a needle in the vein, and the marrow replaces the marrow that was destroyed.
A bone marrow transplant using marrow from a relative or person not related to the patient is called an allogeneic bone marrow transplant. Another type of bone marrow transplant, called autologous bone marrow transplant , is being tested in clinical trials. To do this type of transplant, bone marrow is taken from the patient and treated with drugs to kill any cancer cells. The marrow is then frozen to save it. The patient is given high-dose chemotherapy with or without radiation therapy to destroy all of the remaining marrow. The frozen marrow that was saved is then thawed and given back to the patient through a needle in a vein to replace the marrow that was destroyed. A greater chance for recovery occurs if a doctor chooses a hospital which does more than five bone marrow transplantations per year.
Biological therapy
Biological therapy tries to et the body to fight cancer. It uses materials made by the body or made in a laboratory to boost, direct, or restore the body's natural defenses against disease. Biological therapy is sometimes called biological response modifier (BRM) therapy or immunotherapy. If the spleen is swollen, a doctor may take out the spleen in an operation called a splenectomy.
Standard treatment may be considered because of its effectiveness in patients in past studies, or participation in a clinical trial may be considered. Most patients are not cured with standard therapy and some standard treatments may have more side effects than are desired. For these reasons, clinical trials are designed to find better ways to treat cancer patients and are based on the most up-to-date information. Clinical trials are on going in most parts of the country for patients with CML of any phase. To know more about clinical trials, call the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237); TTY at 1-800-332-8615.
Chronic phase
Treatment may be one of the following:
Accelerated phase
Treatment may be one of the following:
Blastic phase
Treatment may be one of the following:
Meningeal chronic myelogenous leukemia
Treatment may be one of the following:
Refractory
The treatment depends on many factors. A patient may wish to consider entering a clinical trial. If the patient has had a bone marrow transplant, the treatment may be biological therapy or white blood cells from the bone marrow donor may be given to the patient through a vein.
Source:
The National Cancer Institute, May 2001
Last reviewed May 2001 by EBSCO Publishing Editorial Staff
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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