Chronic myelogenous leukemia (CML) is a cancer of the blood and bone marrow. With CML, the bone marrow makes abnormal blood cells including:

  • Myeloblasts—a type of white blood cell, fight infection
  • Red blood cells (RBCs)—carry oxygen
  • Platelets—makes blood clot, stops bleeding in cuts or bruises

CML progresses gradually. It is often slow growing for many years. Eventually, it may transform itself into acute myelogenous leukemia (AML). This is a more aggressive type of leukemia. It progresses much more rapidly and is more serious.

Cancer occurs when cells in the body become abnormal. They divide without control or order. Leukemia is cancer of the white blood cells and their parent cells. Leukemia cells do not function normally. They cannot do what normal blood cells do. In this case they can not fight infections. This means that the person is more likely to become infected with viruses or bacteria. The cancerous cells also overgrow the bone marrow. This forces other normal components, like platelets out. Platelets are needed to help the blood clot. As a results people with leukemia may bleed more easily.

White Blood Cells

White Blood Cells
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CML is almost always associated with a gene mutation. The gene is in a chromosome called the Philadelphia chromosome. This mutation occurs during life. It is not passed from parent to child. In most cases, the cause of the mutation is not known. Studies show that exposure to large doses of radiation is associated with development of CML. This size of the dose would be found in survivors of nuclear accidents or of the atomic bomb blasts. However, most patients with the condition have not been exposed to radiation.

Risk Factors

The following factors increase your chance of developing CML:

  • Sex: male
  • Age: middle age or later
  • Exposure to atomic bomb radiation
  • Exposure to nuclear reactor accident
  • Smoking
    • Smoking is the only lifestyle factor that has been linked to leukemia. Its association with CML is still unclear.


These may also be caused by other, less serious health conditions. See a doctor if you have any of the following:

  • Tiredness
  • Lack of energy
  • Fatigue
  • Unexplained weight loss
  • Night sweats
  • Fever
  • Pain or a feeling of fullness below the ribs
  • Bone pain
  • Joint pain
  • Reduced exercise tolerance
  • Enlargement of the liver or spleen
  • Unexplained bleeding or unusual bruising


Your doctor will ask about your symptoms and medical history. A physical exam will be done. Swelling of the liver; spleen will be looked for. The doctor will also look for swelling in lymph nodes in the armpits, groin, or neck. You will likely be referred to an oncologist. This is a doctor who focuses on treating cancer.

Tests may include the following:

  • Blood tests— to check for changes in the number or appearance of different types of blood cells
  • Bone marrow aspiration—removal of a sample of liquid bone marrow to test for cancer cells
  • Bone marrow biopsy —removal of a sample of liquid bone marrow and a small piece of bone to test for cancer cells
  • Routine microscopic exam——examination of a sample of blood, bone marrow, lymph node tissue, or cerebrospinal fluid
  • Bone, blood marrow, lymph node tissue, or cerebrospinal fluid tests—to distinguish among types of leukemia
  • Cytogenetic analysis—to look for certain changes of the chromosomes (most often to test for Philadelphia chromosome)
  • Chest x-ray —may detect signs of lung infection
  • CT scan —type of x-ray uses a computer to make pictures of structures inside the body
  • MRI scan —uses magnetic waves to make pictures of structures inside the body
  • Ultrasound —uses sound waves to examine masses and organs inside the body


Talk with your doctor about the best plan for you. Treatment options include:

Targeted Drug Therapy

Three drugs work to inhibit the molecule that triggers the development of leukemia and the gene that is associated with it. This medication is often used in early stages of CML. It has replaced chemotherapy and biologic therapy as a treatment of choice. The drugs for this therapy are:


Chemotherapy is the use of drugs to kill cancer cells. It may be given in many forms. This includes by pill, injection, and via a catheter. The drugs enter the bloodstream and travel through the body. While this will focus on cancer cells, some healthy cells are also killed.

Biologic Therapy

This is the use of medications or substances made by the body. The substance is used to increase or restore the body's natural defenses against cancer. This type of therapy is also called biological response modifier therapy. It is still being tested in clinical trials.

High-dose Chemotherapy With Stem Cell Transplant

High doses of chemotherapy are followed by a transplantation of stem cells (immature blood cells). These will replace blood-forming cells destroyed by cancer treatment. Stem cells are removed from the blood or bone marrow of the patient or donor. They are then infused into the patient.

Donor Lymphocyte Infusion

Lymphocytes are a type of white blood cell. A donor’s cells are infused into the patient. The cancer cells do not recognize these cells. They do not attack them.


A splenectomy is a surgery to remove the spleen. It may be done if the spleen has become enlarged from the leukemia. It may also be done if other complications develop.


There are no guidelines for preventing CML. It is possible that smoking is associated with CML. You may reduce your risk by not smoking.