Key Points for This Section

Chronic myelogenous leukemia is a disease in which the bone marrow makes too many white blood cells. Possible signs of chronic myelogenous leukemia include tiredness, night sweats, and fever. Most people with CML have a gene mutation (change) called the Philadelphia chromosome. Tests that examine the blood and bone marrow are used to detect (find) and diagnose chronic myelogenous leukemia. Certain factors affect prognosis (chance of recovery) and treatment options.

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 develop into mature blood cells over time. A blood stem cell may become a myeloid stem cell or a lymphoid stem cell. The lymphoid stem cell develops into a white blood cell. The myeloid stem cell develops into one of three types of mature blood cells:

• Red blood cells that carry oxygen and other materials to all tissues of the body.
• Platelets that help prevent bleeding by causing blood clots to form.
• Granulocytes (white blood cells) that fight infection and disease

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Blood cell development. A blood stem cell goes through several steps to become a red blood cell, platelet, or white blood cell.

In CML, too many blood stem cells develop into a type of white blood cell called granulocytes. These granulocytes are abnormal and do not become healthy white blood cells. They may also be called leukemic cells. The leukemic 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:

• Adult Acute Lymphoblastic Leukemia Treatment ¹
• Childhood Acute Lymphoblastic Leukemia Treatment ²
• Adult Acute Myeloid Leukemia Treatment ³
• Childhood Acute Myeloid Leukemia/Other Myeloid Malignancies Treatment ⁴
• Chronic Lymphocytic Leukemia Treatment ⁵
• Hairy Cell Leukemia Treatment ⁶

Possible signs of chronic myelogenous leukemia include tiredness, night sweats, and fever.

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:

• Feeling very tired.
• Weight loss for no known reason.
• Night sweats.
• Fever.
• Pain or a feeling of fullness below the ribs on the left side.

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.

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Philadelphia chromosome. A piece of chromosome 9 and a piece of chromosome 22 break off and trade places. The bcr-abl gene is formed on chromosome 22 where the piece of chromosome 9 attaches. The changed chromosome 22 is called the Philadelphia chromosome.

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.
• Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:
  • The number of red blood cells, white blood cells, and platelets.
  • The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
  • The portion of the sample made up of red blood cells.

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  Complete blood count (CBC). Blood is collected by inserting a needle into a vein and allowing the blood to flow into a tube. The blood sample is sent to the laboratory and the red blood cells, white blood cells, and platelets are counted. The CBC is used to test for, diagnose, and monitor many different conditions.

• 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.
• 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.
• 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.

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  Bone marrow aspiration and biopsy. After a small area of skin is numbed, a Jamshidi needle (a long, hollow needle) is inserted into the patient’s hip bone. Samples of blood, bone, and bone marrow are removed for examination under a microscope.

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.

Glossary Terms

Not normal. An abnormal lesion or growth may be cancer, premalignant (likely to become cancer), or benign (not cancer).

A condition in which the number of red blood cells is below normal.

An immature blood cell.

A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.

A procedure in which a sample of blood is examined to measure the amounts of certain substances made in the body. An abnormal amount of a substance can be a sign of disease in the organ or tissue that produces it.

A mass of blood that forms when blood platelets, proteins, and cells stick together. When a blood clot is attached to the wall of a blood vessel, it is called a thrombus. When it moves through the bloodstream and blocks the flow of blood in another part of the body, it is called an embolus.

The soft, sponge-like tissue in the center of most bones. It produces white blood cells, red blood cells, and platelets.

The removal of a small sample of bone marrow (usually from the hip) through a needle for examination under a microscope.

The removal of a sample of tissue from the bone marrow with a needle for examination under a microscope.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

Part of a cell that contains genetic information. Except for sperm and eggs, all human cells contain 46 chromosomes.

A slowly progressing disease in which too many white blood cells (not lymphocytes) are made in the bone marrow. Also called chronic myelogenous leukemia, chronic myeloid leukemia, and CML.

A slowly progressing disease in which too many white blood cells (not lymphocytes) are made in the bone marrow. Also called chronic granulocytic leukemia, chronic myeloid leukemia, and CML.

A test to check the number of red blood cells, white blood cells, and platelets in a sample of blood. Also called blood cell count and CBC.

The study of chromosomes and chromosomal abnormalities.

The process of identifying a disease, such as cancer, from its signs and symptoms.

The molecules inside cells that carry genetic information and pass it from one generation to the next. Also called deoxyribonucleic acid.

A protein that speeds up chemical reactions in the body.

Inherited; having to do with information that is passed from parents to offspring through genes in sperm and egg cells.

A type of immune cell that has granules (small particles) with enzymes that are released during infections, allergic reactions, and asthma. Neutrophils, eosinophils, and basophils are granulocytes. A granulocyte is a type of white blood cell. Also called granular leukocyte, PMN, and polymorphonuclear leukocyte.

The substance inside red blood cells that binds to oxygen in the lungs and carries it to the tissues.

Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.

Cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of blood cells to be produced and enter the bloodstream.

Referring to lymphocytes, a type of white blood cell. Also refers to tissue in which lymphocytes develop.

Having to do with or resembling the bone marrow. May also refer to certain types of hematopoietic (blood-forming) cells found in the bone marrow. Sometimes used as a synonym for myelogenous; for example, acute myeloid leukemia and acute myelogenous leukemia are the same disease.

A part of the body that performs a specific function. For example, the heart is an organ.

A colorless, odorless gas. It is needed for animal and plant life. Oxygen that is breathed in enters the blood from the lungs and travels to the tissues.

A doctor who identifies diseases by studying cells and tissues under a microscope.

PDQ is an online database developed and maintained by the National Cancer Institute. Designed to make the most current, credible, and accurate cancer information available to health professionals and the public, PDQ contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, complementary and alternative medicine, and supportive care; a registry of cancer clinical trials from around the world; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care. Most of this information, and more specific information about PDQ, can be found on the NCI's Web site at http://www.cancer.gov/cancertopics/pdq. Also called Physician Data Query.

An abnormality of chromosome 22 in which part of chromosome 9 is transferred to it. Bone marrow cells that contain the Philadelphia chromosome are often found in chronic myelogenous leukemia.

An exam of the body to check for general signs of disease.

A tiny piece of a cell found in the blood that breaks off from a large cell found in the bone marrow. Platelets help wounds heal and prevent bleeding by forming blood clots. Also called thrombocyte.

The likely outcome or course of a disease; the chance of recovery or recurrence.

Cancer that is growing, spreading, or getting worse.

A molecule made up of amino acids that are needed for the body to function properly. Proteins are the basis of body structures such as skin and hair and of substances such as enzymes, cytokines, and antibodies.

A cell that carries oxygen to all parts of the body. Also called erythrocyte and RBC.

An organ that is part of the lymphatic system. The spleen makes lymphocytes, filters the blood, stores blood cells, and destroys old blood cells. It is located on the left side of the abdomen near the stomach.

A cell from which other types of cells develop. For example, blood cells develop from blood-forming stem cells.

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

A group or layer of cells that work together to perform a specific function.

A type of immune cell. Most white blood cells are made in the bone marrow and are found in the blood and lymph tissue. White blood cells help the body fight infections and other diseases. Granulocytes, monocytes, and lymphocytes are white blood cells. Also called leukocyte and WBC.