Facts
Chronic myeloid leukemia (CML) is one type of cancer of the bone marrow and blood. It is also called chronic myelogenous leukemia or chronic myelocytic leukemia.
Seattle Cancer Care Alliance (SCCA) offers comprehensive treatment from a team of experts for all types of leukemia, including CML.
What is chronic myeloid leukemia?
Leukemia begins in the bone marrow.
- In CML, too many blood stem cells become granulocytes — a type of white blood cell.
- The abnormal granulocytes, also called CML or leukemia cells, grow and survive better than normal cells.
- Over time, they crowd out healthy cells your body needs.
Acute leukemia quickly prevents a large proportion of early blood cells from maturing. In chronic leukemia, like CML, more healthy blood cells get a chance to mature, so symptoms usually come on more gradually, and they are less severe at first.
Symptoms
In the early stages, CML usually doesn’t cause symptoms, and it may take years before symptoms develop.
Symptoms of CML are often similar to the flu or other common, less serious diseases. Check with your doctor if you have any of these.
Symptoms from changes in white blood cell counts:
- Flu-like symptoms, such as fever, sweats and body aches
- Blurry vision or other vision changes
- Bone pain
Symptoms from low red blood cells:
- Shortness of breath
- Pale skin
- Fatigue, weakness, lack of energy or sleepiness
Other general symptoms:
- Loss of appetite
- Unexplained weight loss
- Pain or aches in your bones or joints
- Swollen abdomen
- Headaches
- Dizziness
- Vomiting
Diagnosing
If your doctor suspects you may have leukemia, they will want to perform a thorough physical examination and talk with you about your medical history.
An accurate diagnosis of CML requires several tests. You might have any or all of these.
- Blood tests — to check the types and numbers of blood cells, check the amount of hemoglobin (protein that carries oxygen) and look at the size and shape of the cells and whether they contain granules (complete blood count and peripheral blood smear) and to see if leukemic cells are present (immunophenotyping, or flow cytometry). Sometimes CML is discovered during a routine blood test.
- Bone marrow tests — taking samples of bone marrow and a small piece of bone from your pelvis using a needle (bone marrow aspiration and biopsy) and checking them for leukemic cells.
- Chromosome tests — checking your blood or bone marrow cells for changes in chromosomes, such as missing parts of chromosomes or two chromosomes that have exchanged some DNA. These tests include cytogenetic analysis, fluorescent in situ hybridization and polymerase chain reaction.
- Imaging tests — such as chest X-ray, computed tomography (CT) scan, magnetic resonance imaging (MRI) scan or ultrasound to check whether leukemia is impacting other parts of your body.
Phases
Doctors divide CML into phases based on how the disease is behaving and how it is affecting you. Knowing the phase of your disease helps your team recommend the most effective treatment.
How common is CML?
About 9,000 people are diagnosed with CML each year in the U.S.
What causes CML?
Doctors do not know what causes CML.
In almost all cases, CML cells have a chromosomal abnormality known as the Philadelphia chromosome. This means parts of chromosomes 9 and 22 rearranged. Two genes called BCR and ABL fused together in chromosome 22 to make one gene called BCR-ABL. This is called Philadelphia chromosome–positive CML (PH+ CML).
- CML typically affects older people — the average age is 64 — but it can affect people of any age.
- The disease is slightly more common in males than females.
- Exposure to high levels of radiation may increase your risk. However, no link has been shown between dental or medical X-rays and CML.
Keep in mind that most people who develop CML have none of these risk factors, and most people with these risk factors do not develop the disease.
