General Information About Chronic Myeloproliferative Disorders
Chronic Myelogenous Leukemia
Polycythemia Vera
Chronic Idiopathic Myelofibrosis
Essential Thrombocythemia
Chronic Neutrophilic Leukemia
Chronic Eosinophilic Leukemia
Stages of Chronic Myeloproliferative Disorders
Treatment Option Overview
Treatment Options for Chronic Myeloproliferative Disorders

Chronic Myelogenous Leukemia Polycythemia Vera Chronic Idiopathic Myelofibrosis Essential Thrombocythemia Chronic Neutrophilic Leukemia Chronic Eosinophilic Leukemia

To Learn More About Chronic Myeloproliferative Disorders
Get More Information From NCI
Changes to This Summary (08/01/2008)
About PDQ

General Information About Chronic Myeloproliferative Disorders

Key Points for This Section

Myeloproliferative disorders are a group of diseases in which the bone marrow makes too many red blood cells, white blood cells, or platelets. There are 6 types of chronic myeloproliferative disorders. Tests that examine the blood and bone marrow are used to detect (find) and diagnose chronic myeloproliferative disorders.

Myeloproliferative disorders are a group of diseases in which the bone marrow makes too many red blood cells, white blood cells, or platelets.

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.
• White blood cells that fight infection and disease.
• Platelets that help prevent bleeding by causing blood clots to form.

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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 myeloproliferative disorders too many blood stem cells develop into one or more types of blood cells. The disorders usually get worse slowly as the number of extra blood cells increases.

There are 6 types of chronic myeloproliferative disorders.

The type of myeloproliferative disorder is based on whether too many red blood cells, white blood cells, or platelets are being made. Sometimes the body will make too many of more than one type of blood cell, but usually one type of blood cell is affected more than the others are. Chronic myeloproliferative disorders include the following 6 types:

• Chronic myelogenous leukemia.
• Polycythemia vera.
• Chronic idiopathic myelofibrosis.
• Essential thrombocythemia.
• Chronic neutrophilic leukemia.
• Chronic eosinophilic leukemia.

These types are described below. Chronic myeloproliferative disorders sometimes become acute leukemia, in which too many abnormal white blood cells are made.

Tests that examine the blood and bone marrow are used to detect (find) and diagnose chronic myeloproliferative disorders.

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 lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
• Complete blood count (CBC) with differential: A procedure in which a sample of blood is drawn and checked for the following:
  • The number of red blood cells and platelets.
  • The number and type of white blood cells.
  • The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
  • The portion of the blood sample made up of red blood cells.

  Enlarge

  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.

• Bone marrow aspiration and biopsy: The removal of bone marrow, blood, and a small piece of bone by inserting a hollow needle into the hipbone or breastbone. A pathologist views the bone marrow, blood, and bone under a microscope to look for signs of cancer.

  Enlarge

  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.

• 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. Certain diseases or disorders may be diagnosed or ruled out based on the chromosomal changes.

Chronic Myelogenous Leukemia

Chronic myelogenous leukemia is a disease in which too many white blood cells are made in the bone marrow. See the PDQ summary on Chronic Myelogenous Leukemia Treatment ¹ for information on diagnosis, staging, and treatment.

Polycythemia Vera

Key Points for This Section

Polycythemia vera is a disease in which too many red blood cells are made in the bone marrow. Possible signs of polycythemia vera include headaches and a feeling of fullness below the ribs on the left side. Special blood tests are used to diagnose polycythemia vera.

Polycythemia vera is a disease in which too many red blood cells are made in the bone marrow.

In polycythemia vera, the blood becomes thickened with too many red blood cells. The number of white blood cells and platelets may also increase. These extra blood cells may collect in the spleen and cause it to swell. The increased number of red blood cells or platelets in the blood can cause bleeding problems and make clots form in blood vessels. This can cause serious health problems such as stroke or heart attack. In patients older than 65 years, the risk of stroke and heart attack is higher, and polycythemia vera is more likely to become acute myeloid leukemia or chronic idiopathic myelofibrosis.

Possible signs of polycythemia vera include headaches and a feeling of fullness below the ribs on the left side.

Polycythemia vera often does not cause early symptoms. It is sometimes found during a routine blood test. Symptoms may occur as the number of blood cells increases. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:

• A feeling of pressure or fullness below the ribs on the left side.
• Headaches.
• Double vision or seeing dark or blind spots that come and go.
• Itching all over the body, especially after being in warm or hot water.
• Reddened face that looks like a blush or sunburn.
• Weakness.
• Dizziness.
• Weight loss for no known reason.

Special blood tests are used to diagnose polycythemia vera.

In addition to a complete blood count, other special blood tests are used to diagnose polycythemia vera. These tests include the following:

• Arterial blood gas (ABG) test: A test in which a sample of blood is taken from an artery to measure the amount of oxygen and carbon dioxide in the blood and the pH (acidity) of the blood.
• Serum erythropoietin test: A test in which a sample of blood is checked for the level of erythropoietin (a hormone that stimulates new red blood cells to be made).
• Leukocyte alkaline phosphatase (LAP) test: A test in which a sample of blood is checked to measure the amount of alkaline phosphatase (an enzyme) in leukocytes (white blood cells).

Chronic Idiopathic Myelofibrosis

Key Points for This Section

Chronic idiopathic myelofibrosis is a disease in which abnormal blood cells and fibers build up inside the bone marrow. Possible signs of chronic idiopathic myelofibrosis include pain below the ribs on the left side and feeling very tired. A special blood test is used to diagnose chronic idiopathic myelofibrosis. Certain factors affect prognosis (chance of recovery) and treatment options for chronic idiopathic myelofibrosis.

Chronic idiopathic myelofibrosis is a disease in which abnormal blood cells and fibers build up inside the bone marrow.

The bone marrow is made of tissues that make blood cells (red blood cells, white blood cells, and platelets) and a web of fibers that support the blood-forming tissues. In chronic idiopathic myelofibrosis, large numbers of blood stem cells develop into blood cells that do not mature properly (blasts). The web of fibers inside the bone marrow also becomes very thick (like scar tissue) and slows the blood-forming tissue’s ability to make blood cells. This causes the blood-forming tissues to make fewer and fewer blood cells. In order to make up for the low number of blood cells made in the bone marrow, the liver and spleen begin to make the blood cells.

Possible signs of chronic idiopathic myelofibrosis include pain below the ribs on the left side and feeling very tired.

Chronic idiopathic myelofibrosis often does not cause early symptoms. It is sometimes found during a routine blood test. The following symptoms may be caused by chronic idiopathic myelofibrosis or by other conditions. A doctor should be consulted if any of these problems occur:

• Feeling pain or fullness below the ribs on the left side.
• Feeling full sooner than normal when eating.
• Feeling very tired.
• Shortness of breath.
• Easy bruising or bleeding.
• Petechiae (flat, red, pinpoint spots under the skin that are caused by bleeding).
• Fever.
• Night sweats.
• Weight loss.

A special blood test is used to diagnose chronic idiopathic myelofibrosis.

In addition to a complete blood count, bone marrow aspiration and biopsy, and cytogenetic analysis, a peripheral blood smear is used to diagnose chronic idiopathic myelofibrosis. A peripheral blood smear is a procedure in which a sample of blood is checked for tear drop-shaped red blood cells, the number and kinds of white blood cells, the number of platelets, and the presence of blast cells.

Certain factors affect prognosis (chance of recovery) and treatment options for chronic idiopathic myelofibrosis.

Prognosis (chance of recovery) depends on the following:

• The age of the patient.
• The number of abnormal red blood cells and white blood cells.
• The number of blasts in the blood.
• Whether there are certain changes in the chromosomes.
• Whether the patient has symptoms such as fever, night sweats, or weight loss.

Essential Thrombocythemia

Key Points for This Section

Essential thrombocythemia is a disease in which too many platelets are made in the bone marrow. Patients with essential thrombocythemia may have no symptoms. Certain factors affect prognosis (chance of recovery) and treatment options for essential thrombocythemia.

Essential thrombocythemia is a disease in which too many platelets are made in the bone marrow.

Essential thrombocythemia causes an abnormal increase in the number of platelets made in the blood and bone marrow.

Patients with essential thrombocythemia may have no symptoms.

Essential thrombocythemia often does not cause early symptoms. It is sometimes found during a routine blood test. The following symptoms may be caused by essential thrombocytopenia or by other conditions. A doctor should be consulted if any of these problems occur:

• Headache.
• Burning or tingling in the hands or feet.
• Redness and warmth of the hands or feet.
• Vision or hearing problems.

Platelets are sticky. When there are too many platelets, they may clump together and make it hard for the blood to flow. Clots may form in blood vessels and there may also be increased bleeding. These can cause serious health problems such as stroke or heart attack.

Certain factors affect prognosis (chance of recovery) and treatment options for essential thrombocythemia.

Prognosis (chance of recovery) and treatment options depend on the following:

• The age of the patient.
• Whether the patient has symptoms or other problems related to essential thrombocythemia.

Chronic Neutrophilic Leukemia

Chronic neutrophilic leukemia is a disease in which too many blood stem cells develop into a type of white blood cell called neutrophils. Neutrophils are infection -fighting blood cells that surround and destroy dead cells and foreign substances (such as bacteria). The spleen and liver may swell because of the extra neutrophils. Chronic neutrophilic leukemia may stay the same or it may progress quickly to acute leukemia.

Chronic Eosinophilic Leukemia

Key Points for This Section

Chronic eosinophilic leukemia is a disease in which too many white blood cells (eosinophils) are made in the bone marrow. Possible signs of chronic eosinophilic leukemia include fever and feeling very tired.

Chronic eosinophilic leukemia is a disease in which too many white blood cells (eosinophils) are made in the bone marrow.

Eosinophils are white blood cells that react to allergens (substances that cause an allergic response) and help fight infections caused by certain parasites. In chronic eosinophilic leukemia, there are too many eosinophils in the blood, bone marrow, and other tissues. Chronic eosinophilic leukemia may stay the same for many years or it may progress quickly to acute leukemia.

Possible signs of chronic eosinophilic leukemia include fever and feeling very tired.

Chronic eosinophilic leukemia may not cause early symptoms. It is sometimes found during a routine blood test. The following symptoms may be caused by chronic eosinophilic leukemia or by other conditions. A doctor should be consulted if any of these problems occur:

• Fever.
• Feeling very tired.
• Cough.
• Swelling under the skin around the eyes and lips, in the throat, or on the hands and feet.
• Muscle pain.
• Itching.
• Diarrhea.

Stages of Chronic Myeloproliferative Disorders

Key Points for This Section

There is no standard staging system for chronic myeloproliferative disorders. There are three ways that cancer spreads in the body.

There is no standard staging system for chronic myeloproliferative disorders.

Staging is the process used to find out how far the cancer has spread. There is no standard staging system for chronic myeloproliferative disorders. Treatment is based on the type of myeloproliferative disorder the patient has. It is important to know the type in order to plan treatment.

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.

Treatment Option Overview

Key Points for This Section

There are different types of treatment for patients with chronic myeloproliferative disorders. Ten types of standard treatment are used: Watchful waiting Phlebotomy Platelet apheresis Transfusion therapy Chemotherapy Radiation therapy Other drug therapy Surgery Biologic therapy High-dose chemotherapy with stem cell transplant New types of treatment are being tested in clinical trials. Patients may want to think about taking part in a clinical trial. Patients can enter clinical trials before, during, or after starting their cancer treatment. Follow-up tests may be needed.

There are different types of treatment for patients with chronic myeloproliferative disorders.

Different types of treatments are available for patients with chronic myeloproliferative disorders. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Ten types of standard treatment are used:

Watchful waiting

Watchful waiting is closely monitoring a patient’s condition without giving any treatment until symptoms appear or change.

Phlebotomy

Phlebotomy is a procedure in which blood is taken from a vein. A sample of blood may be taken for tests such as a CBC or blood chemistry. Sometimes phlebotomy is used as a treatment and blood is taken from the body to remove extra red blood cells. Phlebotomy is used in this way to treat some chronic myeloproliferative disorders.

Platelet apheresis

Platelet apheresis is a treatment that uses a special machine to remove platelets from the blood. Blood is taken from the patient and put through a blood cell separator where the platelets are removed. The rest of the blood is then returned to the patient’s bloodstream.

Transfusion therapy

Transfusion therapy (blood transfusion) is a method of giving red blood cells, white blood cells, or platelets to replace blood cells destroyed by disease or cancer treatment.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Radiation therapy to treat myeloproliferative disorders is usually directed at the spleen.

Other drug therapy

Anagrelide therapy is used to reduce the risk of blood clots in patients who have too many platelets in their blood. Thalidomide and lenalidomide are drugs that prevent blood vessels from growing into areas of tumor cells.

Surgery

Splenectomy (surgery to remove the spleen) may be done if the spleen is enlarged.

Biologic therapy

Biologic therapy is a treatment that uses the patient's immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body's natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy. Interferon alfa is a biologic agent commonly used to treat some chronic myeloproliferative disorders.

High-dose chemotherapy with stem cell transplant

High-dose chemotherapy with stem cell transplant is a method of giving high doses of chemotherapy and replacing blood-forming cells destroyed by the cancer treatment. Stem cells (immature blood cells) are removed from the blood or bone marrow of the patient or a donor and are frozen and stored. After the chemotherapy is completed, the stored stem cells are thawed and given back to the patient through an infusion. These reinfused stem cells grow into (and restore) the body's blood cells.

New types of treatment are being tested in clinical trials.

Information about clinical trials is available from the NCI Web site ².

Patients may want to think about taking part in a clinical trial.

For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.

Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.

Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.

Patients can enter clinical trials before, during, or after starting their cancer treatment.

Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.

Clinical trials are taking place in many parts of the country. See the Treatment Options section that follows for links to current treatment clinical trials. These have been retrieved from NCI's clinical trials database.

Follow-up tests may be needed.

Some of the tests that were done to diagnose the cancer or to find out the stage of the cancer may be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue, change, or stop treatment may be based on the results of these tests. This is sometimes called re-staging.

Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.

Treatment Options for Chronic Myeloproliferative Disorders

A link to a list of current clinical trials is included for each treatment section. For some types or stages of cancer, there may not be any trials listed. Check with your doctor for clinical trials that are not listed here but may be right for you.

See the PDQ summary on Chronic Myelogenous Leukemia Treatment ¹ for information.

The purpose of treatment for polycythemia vera is to reduce the number of extra blood cells. Treatment of polycythemia vera may include the following:

• Phlebotomy.
• Chemotherapy with or without phlebotomy.
• Biologic therapy using interferon alfa.
• A clinical trial of a new treatment.

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with polycythemia vera ³. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site ⁴.

Treatment of chronic idiopathic myelofibrosis in patients without symptoms is usually watchful waiting.

Treatment of chronic idiopathic myelofibrosis in patients with symptoms may include the following:

• Transfusion of red blood cells to relieve symptoms and improve quality of life.
• Biologic therapy using interferon alfa.
• Splenectomy.
• Radiation therapy to the spleen.
• Chemotherapy.
• Donor stem cell transplant.
• Thalidomide or lenalidomide.

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with chronic idiopathic myelofibrosis ⁵. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site ⁴.

Treatment of essential thrombocythemia in patients younger than 60 years who have no symptoms and an acceptable platelet count is usually watchful waiting. Treatment of other patients may include the following:

• Chemotherapy.
• Anagrelide therapy.
• Biologic therapy using interferon alfa.
• Platelet apheresis.
• A clinical trial of a new treatment.

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with essential thrombocythemia ⁶. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site ⁴.

Treatment of chronic neutrophilic leukemia may include the following:

• Donor bone marrow transplant.
• Chemotherapy.
• Biologic therapy using interferon alfa.
• A clinical trial of a new treatment.

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with chronic neutrophilic leukemia ⁷. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site ⁴.

Treatment of chronic eosinophilic leukemia may include the following:

• Bone marrow transplant.
• Biologic therapy using interferon alfa.
• A clinical trial of a new treatment.

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with chronic eosinophilic leukemia ⁸. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site ⁴.

To Learn More About Chronic Myeloproliferative Disorders

For more information from the National Cancer Institute about chronic myeloproliferative disorders, see the following:

• Myeloproliferative Disorders Home Page ⁹
• Understanding Cancer Series: Blood Stem Cell Transplants ¹⁰
• Biological Therapies for Cancer: Questions and Answers ¹¹
• Bone Marrow Transplantation and Peripheral Blood Stem Cell Transplantation: Questions and Answers ¹²

For general cancer information and other resources from the National Cancer Institute, see the following:

• What You Need to Know About™ Cancer - An Overview ¹³
• Understanding Cancer Series: Cancer ¹⁴
• Staging: Questions and Answers ¹⁵
• Chemotherapy and You: Support for People With Cancer ¹⁶
• Radiation Therapy and You: Support for People With Cancer ¹⁷
• Coping with Cancer ¹⁸
• Support and Resources ¹⁹
• Cancer Library ²⁰
• Information For Survivors/Caregivers/Advocates ²¹

Get More Information From NCI

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Search the NCI Web site

The NCI Web site ²³ provides online access to information on cancer, clinical trials, and other Web sites and organizations that offer support and resources for cancer patients and their families. For a quick search, use our “Best Bets” search box in the upper right hand corner of each Web page. The results that are most closely related to your search term will be listed as Best Bets at the top of the list of search results.

There are also many other places to get materials and information about cancer treatment and services. Hospitals in your area may have information about local and regional agencies that have information on finances, getting to and from treatment, receiving care at home, and dealing with problems related to cancer treatment.

Find Publications

The NCI has booklets and other materials for patients, health professionals, and the public. These publications discuss types of cancer, methods of cancer treatment, coping with cancer, and clinical trials. Some publications provide information on tests for cancer, cancer causes and prevention, cancer statistics, and NCI research activities. NCI materials on these and other topics may be ordered online or printed directly from the NCI Publications Locator ²⁴. These materials can also be ordered by telephone from the Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237), TTY at 1-800-332-8615.

Changes to This Summary (08/01/2008)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Text describing the way cancer spreads in the body was added to the Stages ²⁵ section.

About PDQ

PDQ is a comprehensive cancer database available on NCI's Web site.

PDQ is the National Cancer Institute's (NCI's) comprehensive cancer information database. Most of the information contained in PDQ is available online at NCI's Web site ²³. PDQ is provided as a service of the NCI. The NCI is part of the National Institutes of Health, the federal government's focal point for biomedical research.

PDQ contains cancer information summaries.

The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries are available in two versions. The health professional versions provide detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions provide current and accurate cancer information.

The PDQ cancer information summaries are developed by cancer experts and reviewed regularly.

Editorial Boards made up of experts in oncology and related specialties are responsible for writing and maintaining the cancer information summaries. The summaries are reviewed regularly and changes are made as new information becomes available. The date on each summary ("Date Last Modified") indicates the time of the most recent change.

PDQ also contains information on clinical trials.

A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Listings of clinical trials are included in PDQ and are available online at NCI's Web site ²⁶. Descriptions of the trials are available in health professional and patient versions. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237); TTY at 1-800-332-8615.

Glossary Terms

The area of the body that contains the pancreas, stomach, intestines, liver, gallbladder, and other organs.

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

A rapidly progressing cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of white blood cells to be produced and enter the blood stream.

A quickly progressing disease in which too many immature white blood cells (not lymphocytes) are found in the blood and bone marrow. Also called acute myeloblastic leukemia, acute myelogenous leukemia, acute nonlymphocytic leukemia, AML, and ANLL.

A drug that is used to decrease the number of platelets in the blood in order to prevent blood clotting.

A process in which anything complex is separated into simple or less complex parts.

A procedure in which blood is collected, part of the blood such as platelets or white blood cells is taken out, and the rest of the blood is returned to the donor. Also called pheresis.

A large group of single-cell microorganisms. Some cause infections and disease in animals and humans. The singular of bacteria is bacterium.

A substance that is made from a living organism or its products and is used in the prevention, diagnosis, or treatment of cancer and other diseases. Biologic agents include antibodies, interleukins, and vaccines. Also called biological agent and biological drug.

Treatment to boost or restore the ability of the immune system to fight cancer, infections, and other diseases. Also used to lessen certain side effects that may be caused by some cancer treatments. Agents used in biological therapy include monoclonal antibodies, growth factors, and vaccines. These agents may also have a direct antitumor effect. Also called biological response modifier therapy, biotherapy, BRM therapy, and immunotherapy.

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 administration of blood or blood products into a blood vessel.

A tube through which the blood circulates in the body. Blood vessels include a network of arteries, arterioles, capillaries, venules, and veins.

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.

A procedure to replace bone marrow that has been destroyed by treatment with high doses of anticancer drugs or radiation. Transplantation may be autologous (an individual's own marrow saved before treatment), allogeneic (marrow donated by someone else), or syngeneic (marrow donated by an identical twin).

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.

A flexible tube used to deliver fluids into or withdraw fluids from the body.

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 complete blood count.

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

Treatment with drugs that kill cancer cells.

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

A disease or condition that persists or progresses over a long period of time.

A disease in which too many eosinophils (a type of white blood cell) are found in the bone marrow, blood, and other tissues. Chronic eosinophilic leukemia may stay the same for many years, or it may progress quickly to acute leukemia.

A progressive, chronic disease in which the bone marrow is replaced by fibrous tissue and blood is made in organs such as the liver and the spleen, instead of in the bone marrow. This disease is marked by an enlarged spleen and progressive anemia. Also called agnogenic myeloid metaplasia, idiopathic myelofibrosis, myelosclerosis with myeloid metaplasia, and primary myelofibrosis.

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 disease in which too many neutrophils (a type of white blood cell) are found in the blood. The extra neutrophils may cause the spleen and liver to become enlarged. Chronic neutrophilic leukemia may stay the same for many years or it may progress quickly to acute leukemia.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical study.

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.

Frequent and watery bowel movements.

The amount of medicine taken, or radiation given, at one time.

Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.

A protein that speeds up chemical reactions in the body.

A type of white blood cell.

A substance that is naturally produced by the kidneys, and that stimulates the bone marrow to make red blood cells. When erythropoietin is made in the laboratory, it is called epoetin alfa or epoetin beta.

An increased number of thrombocytes (platelets) in the blood, without a known cause. Also called essential thrombocytosis.

A type of radiation therapy that uses a machine to aim high-energy rays at the cancer from outside of the body. Also called external-beam radiation therapy.

Monitoring a person's health over time after treatment. This includes keeping track of the health of people who participate in a clinical study or clinical trial for a period of time, both during the study and after the study ends.

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

An intensive drug treatment to kill cancer cells, but that also destroys the bone marrow and can cause other severe side effects. High-dose chemotherapy is usually followed by bone marrow or stem cell transplantation to rebuild the bone marrow.

One of many chemicals made by glands in the body. Hormones circulate in the bloodstream and control the actions of certain cells or organs. Some hormones can also be made in the laboratory.

The complex group of organs and cells that defends the body against infections and other diseases.

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.

A method of putting fluids, including drugs, into the bloodstream. Also called intravenous infusion.

Use of a syringe and needle to push fluids or drugs into the body; often called a "shot."

A biological response modifier (a substance that can improve the body's natural response to infections and other diseases). Interferons interfere with the division of cancer cells and can slow tumor growth. There are several types of interferons, including interferon-alpha, -beta, and -gamma. The body normally produces these substances. They are also made in the laboratory to treat cancer and other diseases.

A type of radiation therapy in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called brachytherapy, implant radiation therapy, and radiation brachytherapy.

A drug that is similar to thalidomide, and is used to treat multiple myeloma and certain types of anemia. It is also being studied in the treatment of other types of cancer. Lenalidomide belongs to the family of drugs called angiogenesis inhibitors. Also called CC-5013 and Revlimid.

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.

A 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 infection and other diseases.

A large organ located in the upper abdomen. The liver cleanses the blood and aids in digestion by secreting bile.

A thin tube that carries lymph (lymphatic fluid) and white blood cells through the lymphatic system. Also called lymphatic vessel.

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.

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

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).

Having to do with metastasis, which is the spread of cancer from one part of the body to another.

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 group of slow growing blood cancers, including chronic myelogenous leukemia, in which large numbers of abnormal red blood cells, white blood cells, or platelets grow and spread in the bone marrow and the peripheral blood.

The National Cancer Institute, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. The National Cancer Institute conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the National Cancer Institute Web site at http://www.cancer.gov. Also called NCI.

NCI, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. It conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the NCI Web site at http://www.cancer.gov. Also called National Cancer Institute.

A type of white blood cell.

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.

An animal or plant that gets nutrients by living on or in an organism of another species. A complete parasite gets all of its nutrients from the host organism, but a semi-parasite gets only some of its nutrients from the host.

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.

A procedure in which a sample of blood is viewed under a microscope to count different circulating blood cells (red blood cells, white blood cells, platelets, etc.) and see whether the cells look normal.

Pinpoint, unraised, round red spots under the skin caused by bleeding.

The puncture of a vein with a needle for the purpose of drawing blood. Also called venipuncture.

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

A type of blood cell that helps prevent bleeding by causing blood clots to form. Also called thrombocyte.

A disease in which there are too many red blood cells in the bone marrow and blood, causing the blood to thicken. The number of white blood cells and platelets may also increase. The extra blood cells may collect in the spleen and cause it to become enlarged. They may also cause bleeding problems and make clots form in blood vessels.

The original tumor.

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

In medicine, the course of a disease, such as cancer, as it becomes worse or spreads in the body.

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.

The overall enjoyment of life. Many clinical trials assess the effects of cancer and its treatment on the quality of life. These studies measure aspects of an individual’s sense of well-being and ability to carry out various activities.

Energy released in the form of particle or electromagnetic waves. Common sources of radiation include radon gas, cosmic rays from outer space, medical x-rays, and energy given off by a radioisotope (unstable form of a chemical element that releases radiation as it breaks down and becomes more stable).

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

Giving off radiation.

A small, radioactive pellet that is placed in or near a tumor. Cancer cells are killed by the energy given off as the radioactive material breaks down and becomes more stable.

To come back or to return.

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

Treatment with anticancer drugs directed to a specific area of the body.

The clear liquid part of the blood that remains after blood cells and clotting proteins have been removed.

A problem that occurs when treatment affects healthy tissues or organs. Some common side effects of cancer treatment are fatigue, pain, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.

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.

The bones, muscles, tendons, and other tissues that reach from the base of the skull to the tailbone. The spinal column encloses the spinal cord and the fluid surrounding the spinal cord. Also called backbone, spine, and vertebral column.

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.

An operation to remove the spleen.

The extent of a cancer in the body. Staging is usually based on the size of the tumor, whether lymph nodes contain cancer, and whether the cancer has spread from the original site to other parts of the body.

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.

In medicine, treatment that experts agree is appropriate, accepted, and widely used. Health care providers are obligated to provide patients with standard therapy. Also called best practice and standard of care.

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

A method of replacing immature blood-forming cells that were destroyed by cancer treatment. The stem cells are given to the person after treatment to help the bone marrow recover and continue producing healthy blood cells.

In medicine, a loss of blood flow to part of the brain, which damages brain tissue. Strokes are caused by blood clots and broken blood vessels in the brain. Symptoms include dizziness, numbness, weakness on one side of the body, and problems with talking, writing, or understanding language. The risk of stroke is increased by high blood pressure, older age, smoking, diabetes, high cholesterol, heart disease, atherosclerosis (a build-up of fatty material and plaque inside the coronary arteries), and a family history of stroke.

A procedure to remove or repair a part of the body or to find out whether disease is present. An operation.

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

Treatment with anticancer drugs that travel through the blood to cells all over the body.

A drug that is used to treat multiple myeloma in patients who have just been diagnosed, and a painful skin disease related to leprosy. It is also being studied in the treatment of other types of cancer. Thalidomide belongs to the family of drugs called angiogenesis inhibitors. Also called Thalomid.

Treatment.

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

The infusion of components of blood or whole blood into the bloodstream. The blood may be donated from another person, or it may have been taken from the person earlier and stored until needed.

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancerous), or malignant (cancerous). Also called neoplasm.

Closely monitoring a patient's condition but withholding treatment until symptoms appear or change. Also called active surveillance, expectant management, and observation.

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.

A type of high-energy radiation. In low doses, x-rays are used to diagnose diseases by making pictures of the inside of the body. In high doses, x-rays are used to treat cancer.