Chronic myelogenous leukemia is a disease in which the bone marrow makes too many white blood cells.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 bone marrow makes blood stem cells (immature cells) that become mature blood cells over time. A blood stem cell may become a myeloid stem cell or a lymphoid stem cell. A lymphoid stem cell becomes a white blood cell. A myeloid stem cell becomes one of three types of mature blood cells:
- Platelets that form blood clots to stop bleeding.
- Granulocytes (white blood cells) that fight infection and disease.
In CML, too many blood stem cells become a type of white blood cell called granulocytes. These granulocytes are abnormal and do not become healthy white blood cells. They are also called leukemia cells. The leukemia cells can build up in the blood and bone marrow so there is less room for healthy white blood cells, red blood cells, and platelets. When this happens, infection, anemia, or easy bleeding may occur. This summary is about chronic myelogenous leukemia. See the following PDQ summaries for more information about leukemia:
- Chronic Lymphocytic Leukemia Treatment
- Hairy Cell Leukemia Treatment
Signs and symptoms of chronic myelogenous leukemia include fever, night sweats, and tiredness.These and other signs and symptoms may be caused by CML or by other conditions. Check with your doctor if you have any of the following:
- Feeling very tired.
- Weight loss for no known reason.
- Night sweats.
- Pain or a feeling of fullness below the ribs on the left side.
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 become 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:
- Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease such as an enlarged spleen. A history of the patient’s health habits and past illnesses and treatments will also be taken.
- Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.
- Bone marrow aspiration and biopsy: The removal of bone marrow, blood, and a small piece of bone by inserting a needle into the hipbone or breastbone. A pathologist views the bone marrow, blood, and bone under a microscope to look for abnormal cells.
One of the following tests may be done on the samples of blood or bone marrow tissue that are removed:
- Cytogenetic analysis: A test in which cells in a sample of blood or bone marrow are viewed under a microscope to look for certain changes in the chromosomes, such as the Philadelphia chromosome.
- FISH (fluorescence in situ hybridization): A laboratory technique used to look at genes or chromosomes in cells and tissues. Pieces of DNA that contain a fluorescent dye are made in the laboratory and added to cells or tissues on a glass slide. When these pieces of DNA bind to specific genes or areas of chromosomes on the slide, they light up when viewed under a microscope with a special light.
- Reverse transcription polymerase chain reaction test (RT–PCR): A laboratory test in which cells in a sample of tissue are studied using chemicals to look for certain changes in the structure or function of genes.
Certain factors affect prognosis (chance of recovery) and treatment options.The prognosis (chance of recovery) and treatment options depend on the following:
- The patient’s age.
- The phase of CML.
- The amount of blasts in the blood or bone marrow.
- The size of the spleen at diagnosis.
- The patient’s general health.