National Cancer Institute National Cancer Institute
U.S. National Institutes of Health National Cancer Institute
Send to Printer
Chronic Myelogenous Leukemia Treatment (PDQ®)     
Last Modified: 08/04/2008
Patient Version
Stages of Chronic Myelogenous Leukemia

Key Points for This Section


After chronic myelogenous leukemia has been diagnosed, tests are done to find out if the cancer has spread.

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:

There are three ways that cancer spreads in the body.

When cancer cells spread outside the blood, a solid tumor may form. This process is called metastasis. The three ways that cancer cells spread in the body are:

  • Through the blood. Cancer cells travel through the blood, invade solid tissues in the body, such as the brain or heart, and form a solid tumor.
  • Through the lymph system. Cancer cells invade the lymph system, travel through the lymph vessels, and form a solid tumor in other parts of the body.
  • Through solid tissue. Cancer cells that have formed a solid tumor spread to tissues in the surrounding area.

The new (metastatic) tumor is the same type of cancer as the primary cancer. For example, if leukemia cells spread to the brain, the cancer cells in the brain are actually leukemia cells. The disease is metastatic leukemia, not brain cancer.

Chronic myelogenous leukemia has 3 phases.

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 phase

In chronic phase CML, fewer than 10% of the cells in the blood and bone marrow are blast cells.

Accelerated phase

In accelerated phase CML, 10% to 19% of the cells in the blood and bone marrow are blast cells.

Blastic phase

In 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.



Glossary Terms

abnormal
Not normal. An abnormal lesion or growth may be cancerous, premalignant (likely to become cancer), or benign.
accelerated phase chronic myelogenous leukemia (ak-SEH-leh-ray-ted FAYZ KRAH-nik MY-eh-LAH-jeh-nus loo-KEE-mee-uh)
A phase of chronic myelogenous leukemia in which the disease is progressing. In this phase, 10% to 19% of the cells in the blood and bone marrow are blast cells (immature blood cells).
anemia (a-NEE-mee-a)
A condition in which the number of red blood cells is below normal.
blast
An immature blood cell.
blast crisis (blast KRY-sis)
A phase of chronic myelogenous leukemia in which tiredness, fever, and an enlarged spleen occur during the blastic phase, when more than 30% of the cells in the blood or bone marrow are blast cells (immature blood cells).
blastic phase chronic myelogenous leukemia (BLAS-tik FAYZ KRAH-nik MY-eh-LAH-jeh-nus loo-KEE-mee-uh)
A phase of chronic myelogenous leukemia in which 20% or more of the cells in the blood or bone marrow are blast cells (immature blood cells). When tiredness, fever, and an enlarged spleen occur during the blastic phase, it is called blast crisis.
blood
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.
bone marrow (bone MAYR-oh)
The soft, sponge-like tissue in the center of most bones. It produces white blood cells, red blood cells, and platelets.
bone marrow aspiration (bone MAYR-oh as-pih-RAY-shun)
The removal of a small sample of bone marrow (usually from the hip) through a needle for examination under a microscope.
bone marrow biopsy (bone MAYR-oh BY-op-see)
The removal of a sample of tissue from the bone marrow with a needle for examination under a microscope.
cancer (KAN-ser)
A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.
cell (sel)
The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.
chromosome (KROH-muh-some)
Part of a cell that contains genetic information. Except for sperm and eggs, all human cells contain 46 chromosomes.
chronic myelogenous leukemia (KRAH-nik MY-eh-LAH-jeh-nus loo-KEE-mee-uh)
CML. A slowly progressing disease in which too many white blood cells (not lymphocytes) are made in the bone marrow. Also called CML, chronic granulocytic leukemia, and chronic myeloid leukemia.
chronic phase chronic myelogenous leukemia (KRAH-nik FAYZ KRAH-nik MY-eh-LAH-jeh-nus loo-KEE-mee-uh)
A phase of chronic myelogenous leukemia in which fewer than 10% of the cells in the blood and bone marrow are blast cells (immature blood cells). This phase may last from several months to several years, and there may be no symptoms of leukemia.
cytogenetics (SY-toh-jeh-NEH-tix)
The study of chromosomes and chromosomal abnormalities.
infection
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.
leukemia (loo-KEE-mee-uh)
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.
lymph vessel (limf ...)
A thin tube that carries lymph (lymphatic fluid) and white blood cells through the lymphatic system. Also called lymphatic vessel.
lymphatic system (lim-FA-tik SIS-tem)
The tissues and organs that produce, store, and carry white blood cells that fight infections and other diseases. This system includes the bone marrow, spleen, thymus, lymph nodes, and lymphatic vessels (a network of thin tubes that carry lymph and white blood cells). Lymphatic vessels branch, like blood vessels, into all the tissues of the body.
metastasis (meh-TAS-tuh-sis)
The spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a “metastatic tumor” or a “metastasis.” The metastatic tumor contains cells that are like those in the original (primary) tumor. The plural form of metastasis is metastases (meh-TAS-tuh-SEEZ).
metastatic (meh-tuh-STA-tik)
Having to do with metastasis, which is the spread of cancer from one part of the body to another.
pathologist (puh-THAH-loh-jist)
A doctor who identifies diseases by studying cells and tissues under a microscope.
Philadelphia chromosome
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.
platelet (PLATE-let)
A type of blood cell that helps prevent bleeding by causing blood clots to form. Also called a thrombocyte.
primary tumor
The original tumor.
red blood cell
RBC. A cell that carries oxygen to all parts of the body. Also called RBC and erythrocyte.
solid tumor
An abnormal mass of tissue that usually does not contain cysts or liquid areas. Solid tumors may be benign (not cancerous), or malignant (cancerous). Different types of solid tumors are named for the type of cells that form them. Examples of solid tumors are sarcomas, carcinomas, and lymphomas. Leukemias (cancers of the blood) generally do not form solid tumors.
spleen
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.
staging (STAY-jing)
Performing exams and tests to learn the extent of the cancer within the body, especially whether the disease has spread from the original site to other parts of the body. It is important to know the stage of the disease in order to plan the best treatment.
symptom
An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.
tissue (TISH-oo)
A group or layer of cells that work together to perform a specific function.
white blood cell
Refers to a blood cell that does not contain hemoglobin. White blood cells include lymphocytes, neutrophils, eosinophils, macrophages, and mast cells. These cells are made by bone marrow and help the body fight infections and other diseases. Also called WBC.