Chronic myelogenous leukemia (also called CML or chronic granulocytic leukemia) is a slowly progressing blood and bone marrow disease that usually occurs during or after middle age, and rarely occurs in children. Normally, the body produces bone marrow stem cells (immature cells) that develop into mature blood cells.
There are 3 types of mature blood cells:
In CML, the body tells too many bone marrow stem cells to develop into a type of white blood cell called granulocytes. Some of these bone marrow stem cells never become mature white blood cells. These are called blasts. Over time, the granulocytes and blasts crowd out the red blood cells and platelets in the bone marrow.
This summary is about chronic myelogenous leukemia. Refer to the following PDQ summaries for more information about leukemia:
These and other symptoms may be caused by CML. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:
Sometimes CML does not cause any symptoms at all.
Most people with CML have a gene mutation (change) called the Philadelphia chromosome.Every cell in the body contains DNA (genetic material) that determines how the cell looks and acts. DNA is contained inside chromosomes. In CML, part of the DNA from one chromosome moves to another chromosome. This change is called the “Philadelphia chromosome.” It results in the bone marrow making an enzyme, called tyrosine kinase, that causes too many stem cells to develop into white blood cells (granulocytes or blasts).
The Philadelphia chromosome is not passed from parent to child.
Tests that examine the blood and bone marrow are used to detect (find) and diagnose chronic myelogenous leukemia.The following tests and procedures may be used:
The prognosis (chance of recovery) and treatment options depend on the following:
Staging is the process used to find out how far the cancer has spread. There is no standard staging system for chronic myelogenous leukemia (CML). Instead, the disease is classified by phase: chronic phase, accelerated phase, or blastic phase. It is important to know the phase in order to plan treatment. The following tests and procedures may be used to find out the phase:
As the amount of blast cells increases in the blood and bone marrow, there is less room for healthy white blood cells, red blood cells, and platelets. This may result in infections, anemia, and easy bleeding, as well as bone pain and pain or a feeling of fullness below the ribs on the left side. The number of blast cells in the blood and bone marrow and the severity of symptoms determine the phase of the disease.
Chronic phaseIn chronic phase CML, fewer than 10% of the cells in the blood and bone marrow are blast cells.
Accelerated phaseIn accelerated phase CML, 10% to 19% of the cells in the blood and bone marrow are blast cells.
Blastic phaseIn blastic phase CML, 20% or more of the cells in the blood or bone marrow are blast cells. When tiredness, fever, and an enlarged spleen occur during the blastic phase, it is called blast crisis.
In relapsed CML, the number of blast cells increases after a remission.
Different types of treatment are available for patients with chronic myelogenous leukemia (CML). Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.
Clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site. Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.
Six types of standard treatment are used:Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.
Other drug therapyImatinib (Gleevec) is a new type of cancer drug, called a tyrosine kinase inhibitor. It blocks the enzyme, tyrosine kinase, that causes stem cells to develop into more white blood cells (granulocytes or blasts) than the body needs.
Biologic therapyBiologic therapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy.
High-dose chemotherapy with stem cell transplantHigh-dose chemotherapy with stem cell transplant is a method of giving high doses of chemotherapy and replacing blood-forming cells destroyed by the cancer treatment. Stem cells (immature blood cells) are removed from the blood or bone marrow of the patient or a donor and are frozen and stored. After the chemotherapy is completed, the stored stem cells are thawed and given back to the patient through an infusion. These reinfused stem cells grow into (and restore) the body’s blood cells.
Donor lymphocyte infusion (DLI)Donor lymphocyte infusion (DLI) is a cancer treatment that may be used after stem cell transplant. Lymphocytes (a type of white blood cell) from the stem cell transplant donor are removed from the donor’s blood and may be frozen for storage. The donor’s lymphocytes are thawed if they were frozen and then given to the patient through one or more infusions. The lymphocytes see the patient’s cancer cells as not belonging to the body and attack them.
SurgerySplenectomy is surgery to remove the spleen.
New types of treatment are being tested in clinical trials.Information about ongoing clinical trials is available from the NCI Web site.
Treatment of chronic phase chronic myelogenous leukemia may include the following:
This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.
Treatment of accelerated phase chronic myelogenous leukemia may include the following:
Information about ongoing clinical trials is available from the NCI Web site.
Treatment of blastic phase chronic myelogenous leukemia may include the following:
Information about ongoing clinical trials is available from the NCI Web site.
Treatment of relapsed chronic myelogenous leukemia may include the following:
This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.