General Information About Childhood Acute Lymphoblastic Leukemia
Stages of Childhood Acute Lymphoblastic Leukemia
Recurrent Childhood Acute Lymphoblastic Leukemia
Treatment Option Overview
Treatment Options for Childhood Acute Lymphoblastic Leukemia

Untreated Childhood Acute Lymphoblastic Leukemia Childhood Acute Lymphoblastic Leukemia Subgroups Recurrent Childhood Acute Lymphoblastic Leukemia

To Learn More About Childhood Acute Lymphoblastic Leukemia
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Changes to This Summary (08/01/2008)
About PDQ

General Information About Childhood Acute Lymphoblastic Leukemia

Key Points for This Section

Childhood acute lymphoblastic leukemia (ALL) is a type of cancer in which the bone marrow makes too many lymphocytes (a type of white blood cell). There are subgroups of childhood ALL. Family history and exposure to radiation may affect the risk of developing childhood ALL. Possible signs of childhood ALL include fever and bruising. Tests that examine the blood and bone marrow are used to detect (find) and diagnose childhood ALL. Certain factors affect prognosis (chance of recovery) and treatment options.

Childhood acute lymphoblastic leukemia (ALL) is a type of cancer in which the bone marrow makes too many lymphocytes (a type of white blood cell).

Childhood acute lymphoblastic leukemia (also called acute lymphocytic leukemia or ALL) is a cancer of the blood and bone marrow. This type of cancer usually gets worse quickly if it is not treated. It is the most common type of cancer 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 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.

The lymphoid stem cell develops into a lymphoblast cell and then into one of three types of lymphocytes (white blood cells):

• B lymphocytes that make antibodies to help fight infection.
• T lymphocytes that help B lymphocytes make the antibodies that help fight infection.
• Natural killer cells that attack cancer cells and viruses.

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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 ALL, too many stem cells develop into lymphoblasts or lymphocytes. These cells may also be called leukemic cells. The leukemic cells are not able to fight infection very well. Also, as the number of lymphocytes increases in the blood and bone marrow, there is less room for healthy white blood cells, red blood cells, and platelets. This may lead to infection, anemia, and easy bleeding.

This summary is about acute lymphoblastic leukemia. See the following PDQ summaries for information on other types of leukemia:

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

There are subgroups of childhood ALL.

Four of the subgroups of ALL are based on the type of blood cell that is affected, whether there are certain changes in the chromosomes, and age at diagnosis:

• T cell ALL.
• Philadelphia chromosome positive ALL.
• ALL diagnosed in an infant.
• ALL diagnosed in children who are aged 10 and older and adolescents (teenagers).

These subgroups are treated differently from other types of ALL. (See the Childhood Acute Lymphoblastic Leukemia Subgroups ⁷ section for more information.)

Family history and exposure to radiation may affect the risk of developing childhood ALL.

Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor. Possible risk factors for ALL include the following:

• Having a brother or sister with leukemia.
• Being white or Hispanic.
• Living in the United States.
• Being exposed to x-rays before birth.
• Being exposed to radiation.
• Past treatment with chemotherapy or other drugs that weaken the immune system.
• Having certain genetic disorders, such as Down syndrome.

Possible signs of childhood ALL include fever and bruising.

These and other symptoms may be caused by childhood ALL. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:

• Fever.
• Easy bruising or bleeding.
• Petechiae (flat, pinpoint spots under the skin caused by bleeding).
• Bone or joint pain.
• Painless lumps in the neck, underarm, stomach, or groin.
• Pain or feeling of fullness below the ribs.
• Weakness or feeling tired.
• Loss of appetite.

Tests that examine the blood and bone marrow are used to detect (find) and diagnose childhood ALL.

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 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.



• Cytogenetic analysis: A laboratory test in which the cells in a sample of blood or bone marrow are viewed under a microscope to look for certain changes in the chromosomes in the lymphocytes. For example, in ALL, part of one chromosome is moved to another chromosome. This is called the “ Philadelphia chromosome.”

  Enlarge

  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.




• Immunophenotyping: A test in which the cells in a sample of blood or bone marrow are looked at under a microscope to find out if malignant lymphocytes (cancer) began from the B lymphocytes or the T lymphocytes.



• 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.



• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.

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

The prognosis (chance of recovery) and treatment options depend on:

• Age and white blood cell count at diagnosis.
• How quickly and how low the leukemia cell count drops after initial treatment.
• Gender and race.
• Whether the leukemia cells began from the B lymphocytes or the T lymphocytes.
• Whether there are certain changes in the chromosomes of lymphocytes.
• Whether the leukemia has spread to the brain and spinal cord.
• Whether the child has Down syndrome.

Stages of Childhood Acute Lymphoblastic Leukemia

Key Points for This Section

Once childhood ALL has been diagnosed, tests are done to find out if the cancer has spread to the central nervous system (brain and spinal cord), testicles, or to other parts of the body. There are three ways that cancer spreads in the body. In childhood ALL, risk groups are used instead of stages.

Once childhood ALL has been diagnosed, tests are done to find out if the cancer has spread to the central nervous system (brain and spinal cord), testicles, or to other parts of the body.

The extent or spread of cancer is usually described as stages. For childhood acute lymphoblastic leukemia (ALL), risk groups are used instead of stages. The following tests and procedures may be used to determine the risk group:

• Lumbar puncture: A procedure used to collect cerebrospinal fluid from the spinal column. This is done by placing a needle into the spinal column. This procedure is also called an LP or spinal tap.
• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
• Testicular biopsy: The removal of cells or tissues from the testicles so they can be viewed under a microscope by a pathologist to check for signs of cancer. This procedure is done only if there seems to be anything unusual about the testicles during the physical exam.

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.

In childhood ALL, risk groups are used instead of stages.

Risk groups are described as:

• Standard (low) risk: Includes children aged 1 to 9 years who have a white blood cell count of less than 50,000/µL at diagnosis.
• High risk: Includes children younger than 1 year or older than 9 years and children who have a white blood cell count of 50,000/µL or more at diagnosis.

It is important to know the risk group in order to plan treatment.

Recurrent Childhood Acute Lymphoblastic Leukemia

Recurrent childhood ALL is cancer that has recurred (come back) after it has been treated. The leukemia may come back in the blood and bone marrow, brain, testicles, spinal cord, or in other parts of the body.

Treatment Option Overview

Key Points for This Section

There are different types of treatment for childhood acute lymphoblastic leukemia (ALL). Children with ALL should have their treatment planned by a team of doctors with expertise in treating childhood leukemia. The treatment of childhood ALL usually has 3 phases. Three types of standard treatment are used: Chemotherapy Radiation therapy Chemotherapy with stem cell transplant New types of treatment are being tested in clinical trials. High-dose chemotherapy Other drug therapy 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 childhood acute lymphoblastic leukemia (ALL).

Different types of treatment are available for children with acute lymphoblastic leukemia (ALL). 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 for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.

Because cancer in children is rare, taking part in a clinical trial should be considered. Some clinical trials are open only to patients who have not started treatment.

Children with ALL should have their treatment planned by a team of doctors with expertise in treating childhood leukemia.

Treatment will be overseen by a pediatric oncologist, a doctor who specializes in treating children with cancer. The pediatric oncologist works with other pediatric health professionals who are experts in treating children with leukemia and who specialize in certain areas of medicine. These may include the following specialists:

• Hematologist.
• Medical oncologist.
• Pediatric surgeon.
• Radiation oncologist.
• Endocrinologist.
• Neurologist.
• Neuropathologist.
• Neuroradiologist.
• Pediatric nurse specialist.
• Social worker.
• Rehabilitation specialist.
• Psychologist.

Regular follow-up exams are very important. Side effects can result from treatment long after it ends. These are called late effects. Radiation therapy to the head may affect the child's developing brain and cause changes in mood, feelings, thinking, learning, or memory. Late effects of treatment for ALL also include the risk of second cancers (new types of cancer), especially brain tumors. Early diagnosis and treatment of these secondary brain tumors may help lower the risk from these brain tumors. Children younger than 4 years have a higher risk of side effects from radiation therapy to the brain. It is important to talk with your child's doctors about the possible late effects caused by some treatments. See the PDQ summary on Late Effects of Treatment for Childhood Cancer ⁸.

The treatment of childhood ALL usually has 3 phases.

The treatment of childhood ALL is done in phases:

• Induction therapy: This is the first phase of treatment. Its purpose is to kill the leukemia cells in the blood and bone marrow. This puts the leukemia into remission. This is also called the remission induction phase.
• Consolidation /intensification therapy: This is the second phase of therapy. It begins once the leukemia is in remission. The purpose of consolidation/intensification therapy is to kill any remaining leukemia cells that may not be active but could begin to regrow and cause a relapse.
• Maintenance therapy: This is the third phase of treatment. Its purpose is to kill any remaining leukemia cells that may regrow and cause a relapse. Often the cancer treatments are given in lower doses than those used for induction and consolidation/intensification therapy. This is also called the continuation therapy phase.

Bone marrow biopsy and aspirates are done throughout all phases to see how well the leukemia is responding to treatment.

Treatment called central nervous system (CNS) sanctuary therapy is usually given during each phase of therapy. Because chemotherapy that is given by mouth or injected into a vein may not reach leukemia cells in the CNS (brain and spinal cord), the cells are able to find “sanctuary” (hide) in the CNS. Intrathecal chemotherapy and radiation therapy are able to reach leukemia cells in the CNS and are given to kill the leukemia cells and prevent the cancer from recurring (coming back). CNS sanctuary therapy is also called CNS prophylaxis.

Three types of standard treatment are used:

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 (intrathecal), an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). Combination chemotherapy is treatment using more than one anticancer drug. The way the chemotherapy is given depends on the type of the cancer being treated.

Intrathecal chemotherapy may be used to treat childhood ALL that has spread, or may spread, to the brain and spinal cord. When used to prevent cancer from spreading to the brain and spinal cord, it is called central nervous system (CNS) sanctuary therapy or CNS prophylaxis. Intrathecal chemotherapy is given in addition to chemotherapy by mouth or vein.

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. External radiation therapy may be used to treat childhood ALL that has spread, or may spread, to the brain and spinal cord. When used this way, it is called central nervous system (CNS) sanctuary therapy or CNS prophylaxis.

Because radiation therapy to the brain can affect growth and brain development in young children, clinical trials are studying new ways of using radiation therapy that may have fewer side effects, including lower doses and fractionation (dividing the total dose of radiation therapy into several smaller, equal doses delivered over a period of several days).

Chemotherapy with stem cell transplant

Stem cell transplant is a method of giving 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 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. A stem cell transplant using stem cells from a donor who is not related to the patient is being studied in clinical trials.

New types of treatment are being tested in clinical trials.

This summary section describes treatments that are being studied in clinical trials. It may not mention every new treatment being studied. Information about clinical trials is available from the NCI Web site ⁹.

High-dose chemotherapy

High-dose chemotherapy is giving high doses of anticancer drugs to kill cancer cells. This treatment often causes the bone marrow to stop making blood cells and can cause other serious side effects. High-dose chemotherapy is usually followed by stem cell transplant to restore the bone marrow. Clinical trials are studying high-dose chemotherapy for certain patients, including children whose ALL does not go into remission after induction therapy.

Other drug therapy

Imatinib mesylate (Gleevec) is a type of anticancer drug called a tyrosine kinase inhibitor. It blocks the enzyme, tyrosine kinase, that causes stem cells to develop into more white blood cells (granulocytes or blasts) than the body needs.

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 Childhood Acute Lymphoblastic Leukemia

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.

Standard treatment of childhood acute lymphoblastic leukemia (ALL) during the induction, consolidation /intensification, and maintenance phases may include the following:

• Combination chemotherapy.
• CNS sanctuary therapy with intrathecal chemotherapy and/or radiation therapy to the brain.

Some of the treatments being studied in clinical trials for childhood ALL include the following:

• Combination chemotherapy with or without intrathecal chemotherapy. Radiation therapy to brain may also be given.
• Combination chemotherapy followed by stem cell transplant using stem cells donated by a brother or sister.

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with untreated childhood acute lymphoblastic leukemia ¹⁰. 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 ¹¹.

Standard treatment of T-cell childhood acute lymphoblastic leukemia (ALL) is usually combination chemotherapy. CNS sanctuary therapy with intrathecal chemotherapy and/or radiation therapy to the brain may also be given. One of the treatments being studied in clinical trials for T-cell childhood ALL is a new kind of anticancer drug.

Treatment of infants with ALL is usually a clinical trial of systemic chemotherapy with intrathecal chemotherapy or chemotherapy followed by a donor stem cell transplant.

Treatment of ALL in older children and adolescents usually involves more aggressive therapy (stronger treatments and higher doses) than that given to children aged 1-9 years.

Standard treatment of Philadelphia chromosome -positive childhood ALL is usually a stem cell transplant using stem cells donated by a brother or sister. One of the treatments being studied in clinical trials for Philadelphia chromosome-positive childhood ALL is imatinib mesylate (Gleevec).

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with T-cell childhood acute lymphoblastic leukemia ¹² and Philadelphia chromosome positive childhood precursor acute lymphoblastic leukemia ¹³. 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 ¹¹.

Standard treatment of recurrent childhood acute lymphoblastic leukemia (ALL) may include the following:

• Combination chemotherapy.
• Systemic chemotherapy and intrathecal chemotherapy with or without radiation therapy to the brain and spinal cord.
• Chemotherapy with stem cell transplant, using stem cells from a donor who is related to the patient, with or without total-body irradiation.
• Chemotherapy plus radiation therapy for cancer that recurs in the testicles only.

Some of the treatments being studied in clinical trials for recurrent childhood ALL include the following:

• A clinical trial of chemotherapy with stem cell transplant, using stem cells from a donor who is not related to the patient, with or without total-body irradiation.
• A clinical trial of new anticancer drugs and new combination chemotherapy treatments.

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with recurrent childhood acute lymphoblastic leukemia ¹⁴. 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 ¹¹.

To Learn More About Childhood Acute Lymphoblastic Leukemia

For more information from the National Cancer Institute about childhood acute lymphoblastic leukemia, see the following:

• What You Need To Know About™ Leukemia ¹⁵
• Understanding Cancer Series: Blood Stem Cell Transplants ¹⁶
• Acute Lymphoblastic Leukemia in Children ¹⁷
• Bone Marrow Transplantation and Peripheral Blood Stem Cell Transplantation: Questions and Answers ¹⁸

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

• What You Need to Know About™ Cancer - An Overview ¹⁹
• Childhood Cancers ²⁰
• CureSearch - National Childhood Cancer Foundation Children’s Oncology Group ²¹
• Late Effects of Treatment for Childhood Cancer ⁸
• Young People with Cancer: A Handbook for Parents ²²
• Care for Children and Adolescents with Cancer: Questions and Answers ²³
• Understanding Cancer Series: Cancer ²⁴
• Staging: Questions and Answers ²⁵
• Coping with Cancer ²⁶
• Support and Resources ²⁷
• Cancer Library ²⁸
• Information for Survivors/Caregivers/Advocates ²⁹

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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 ³³ 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 ³¹. 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." In the United States, about two-thirds of children with cancer are treated in a clinical trial at some point in their illness.

Listings of clinical trials are included in PDQ and are available online at NCI's Web site ³⁴. Descriptions of the trials are available in health professional and patient versions. For additional help in locating a childhood cancer clinical trial, call the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237), TTY at 1-800-332-8615.

The PDQ database contains listings of groups specializing in clinical trials.

The Children's Oncology Group (COG) is the major group that organizes clinical trials for childhood cancers in the United States. Information about contacting COG is available on the NCI Web site ³¹ or from the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237), TTY at 1-800-332-8615.

The PDQ database contains listings of cancer health professionals and hospitals with cancer programs.

Because cancer in children and adolescents is rare, the majority of children with cancer are treated by health professionals specializing in childhood cancers, at hospitals or cancer centers with special facilities to treat them. The PDQ database contains listings of health professionals who specialize in childhood cancer and listings of hospitals with cancer programs. For help locating childhood cancer health professionals or a hospital with cancer programs, call the Cancer Information Service at 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.

An aggressive (fast-growing) type of leukemia (blood cancer) in which too many lymphoblasts (immature white blood cells) are found in the blood and bone marrow. Also called acute lymphocytic leukemia and ALL.

An aggressive (fast-growing) type of leukemia (blood cancer) in which too many lymphoblasts (immature white blood cells) are found in the blood and bone marrow. Also called acute lymphoblastic leukemia and acute lymphocytic leukemia.

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

A type of protein made by plasma cells (a type of white blood cell) in response to an antigen (foreign substance). Each antibody can bind to only one specific antigen. The purpose of this binding is to help destroy the antigen. Antibodies can work in several ways, depending on the nature of the antigen. Some antibodies destroy antigens directly. Others make it easier for white blood cells to destroy the antigen.

A type of immune cell that makes proteins called antibodies, which bind to microorganisms and other foreign substances, and help fight infections. A B lymphocyte is a type of white blood cell. Also called B cell.

The removal of cells or tissues for examination by a pathologist. The pathologist may study the tissue under a microscope or perform other tests on the cells or tissue. There are many different types of biopsy procedures. The most common types include: (1) incisional biopsy, in which only a sample of tissue is removed; (2) excisional biopsy, in which an entire lump or suspicious area is removed; and (3) needle biopsy, in which a sample of tissue or fluid is removed with a needle. When a wide needle is used, the procedure is called a core biopsy. When a thin needle is used, the procedure is called a fine-needle aspiration biopsy.

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 growth of abnormal cells in the tissues of the brain. Brain tumors can be benign (not cancer) or malignant (cancer).

A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also 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 hollow area or hole. It may describe a body cavity (such as the space within the abdomen) or a hole in a tooth caused by decay.

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

Chemotherapy or radiation therapy given to the central nervous system (CNS) as a preventive treatment. It kills cancer cells that may be in the brain and spinal cord, even though no cancer has been detected there. Also called central nervous system prophylaxis, CNS prophylaxis, and CNS sanctuary therapy.

The fluid that flows in and around the hollow spaces of the brain and spinal cord, and between two of the meninges (the thin layers of tissue that cover and protect the brain and spinal cord). Cerebrospinal fluid is made by tissue called the choroid plexus in the ventricles (hollow spaces) in the brain. Also called CSF.

Treatment with drugs that kill cancer cells.

An x-ray of the structures inside the chest. An x-ray is a type of high-energy radiation that can go through the body and onto film, making pictures of areas inside the chest, which can be used to diagnose disease.

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

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.

Chemotherapy or radiation therapy given to the central nervous system (CNS) as a preventive treatment. It kills cancer cells that may be in the brain and spinal cord, even though no cancer has been detected there. Also called central nervous system prophylaxis, central nervous system sanctuary therapy, and CNS prophylaxis.

Treatment using more than one anticancer drug.

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.

Treatment that is given after cancer has disappeared following the initial therapy. Consolidation therapy is used to kill any cancer cells that may be left in the body. It may include radiation therapy, a stem cell transplant, or treatment with drugs that kill cancer cells. Also called intensification therapy and postremission therapy.

The study of chromosomes and chromosomal abnormalities.

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

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

A disorder caused by the presence of an extra chromosome 21 and characterized by mental retardation and distinguishing physical features.

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 doctor who specializes in diagnosing and treating hormone disorders.

A protein that speeds up chemical reactions in the body.

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.

Dividing the total dose of radiation therapy into several smaller, equal doses delivered over a period of several days.

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 area where the thigh meets the abdomen.

A doctor who specializes in treating blood disorders.

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.

A drug used to treat different types of leukemia and other cancers of the blood, gastrointestinal stromal tumors, skin tumors called dermatofibrosarcoma protuberans, and a rare condition called systemic mastocytosis. It is also being studied in the treatment of other types of cancer. Imatinib mesylate blocks the protein made by the bcr/abl oncogene. It is a type of tyrosine kinase inhibitor. Also called Gleevec and STI571.

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

A process used to identify cells, based on the types of antigens or markers on the surface of the cell. This process is used to diagnose specific types of leukemia and lymphoma by comparing the cancer cells to normal cells of the immune system.

Initial treatment used to reduce a cancer. Induction therapy is followed by other treatments, such as chemotherapy, radiation therapy, and hormone therapy to get rid of cancer that remains. Also called first-line therapy, primary therapy, and primary treatment.

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."

Treatment that is given after cancer has disappeared following the initial therapy. Intensification therapy is used to kill any cancer cells that may be left in the body. It may include radiation therapy, a stem cell transplant, or treatment with drugs that kill cancer cells. Also called consolidation therapy and postremission therapy.

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.

Treatment in which anticancer drugs are injected into the fluid-filled space between the thin layers of tissue that cover the brain and spinal cord.

Side effects of cancer treatment that appear months or years after treatment has ended. Late effects include physical and mental problems and second cancers.

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 procedure in which a thin needle called a spinal needle is put into the lower part of the spinal column to collect cerebrospinal fluid or to give drugs. Also called spinal tap.

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.

A lymphocyte that has gotten larger after being stimulated by an antigen. Lymphoblast also refers to an immature cell that can develop into a mature lymphocyte.

A type of immune cell that is made in the bone marrow and is found in the blood and in lymph tissue. The two main types of lymphocytes are B lymphocytes and T lymphocytes. B lymphocytes make antibodies, and T lymphocytes help kill tumor cells and help control immune responses. A lymphocyte is a type of white blood cell.

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

Treatment that is given to help keep cancer from coming back after it has disappeared following the initial therapy. It may include treatment with drugs, vaccines, or antibodies that kill cancer cells, and it may be given for a long time.

Cancerous. Malignant tumors can invade and destroy nearby tissue and spread to other parts of the body.

A doctor who specializes in diagnosing and treating cancer using chemotherapy, hormonal therapy, and biological therapy. A medical oncologist often is the main health care provider for someone who has cancer. A medical oncologist also gives supportive care and may coordinate treatment given by other specialists.

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.

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.

A type of immune cell that has granules (small particles) with enzymes that can kill tumor cells or cells infected with a virus. A natural killer cell is a type of white blood cell. Also called NK cell and NK-LGL.

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 doctor who specializes in the diagnosis and treatment of disorders of the nervous system.

A pathologist who specializes in diseases of the nervous system. A pathologist identifies disease by studying cells and tissues under a microscope.

A doctor trained in radiology who specializes in creating and interpreting pictures of the nervous system. The pictures are produced using forms of radiation, such as x-rays, sound waves, or other types of energy.

A doctor who specializes in treating cancer. Some oncologists specialize in a particular type of cancer treatment. For example, a radiation oncologist specializes in treating cancer with radiation.

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.

Having to do with children.

A registered nurse with an advanced degree in nursing who specializes in the care of children.

A surgeon who specializes in the treatment of children. A surgeon removes or repairs a part of the body by operating on the patient.

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

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 original tumor.

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

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 specialist who can talk with patients and their families about emotional and personal matters, and can help them make decisions.

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).

A doctor who specializes in using radiation to treat cancer.

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.

Cancer that has recurred (come back), usually after a period of time during which the cancer could not be detected. The cancer may come back to the same place as the original (primary) tumor or to another place in the body. Also called recurrence.

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.

A healthcare professional who helps people recover from an illness or injury and return to daily life. Examples of rehabilitation specialists are physical therapists and occupational therapists.

The return of signs and symptoms of cancer after a period of improvement.

A decrease in or disappearance of signs and symptoms of cancer. In partial remission, some, but not all, signs and symptoms of cancer have disappeared. In complete remission, all signs and symptoms of cancer have disappeared, although cancer still may be in the body.

Something that may increase the chance of developing a disease. Some examples of risk factors for cancer include age, a family history of certain cancers, use of tobacco products, certain eating habits, obesity, lack of exercise, exposure to radiation or other cancer-causing agents, and certain genetic changes.

Refers to a new primary cancer in a person with a history of cancer.

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.

A professional trained to talk with people and their families about emotional or physical needs, and to find them support services.

An abnormal mass of tissue that usually does not contain cysts or liquid areas. Solid tumors may be benign (not cancer), or malignant (cancer). 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.

A column of nerve tissue that runs from the base of the skull down the back. It is surrounded by three protective membranes, and is enclosed within the vertebrae (back bones). The spinal cord and the brain make up the central nervous system, and spinal cord nerves carry most messages between the brain and the rest of the body.

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.

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.

An organ that is part of the digestive system. The stomach helps digest food by mixing it with digestive juices and churning it into a thin liquid.

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 type of immune cell that can attack foreign cells, cancer cells, and cells infected with a virus. T cells can also help control immune responses. A T cell is a type of white blood cell. Also called T lymphocyte and thymocyte.

One of two egg-shaped glands inside the scrotum that produce sperm and male hormones. Also called testis.

Treatment.

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

Radiation therapy to the entire body. It is usually followed by bone marrow or peripheral stem cell transplantation.

A drug that interferes with cell communication and growth and may prevent tumor growth. Some tyrosine kinase inhibitors are used to treat cancer.

A blood vessel that carries blood to the heart from tissues and organs in the body.

In medicine, a very simple microorganism that infects cells and may cause disease. Because viruses can multiply only inside infected cells, they are not considered to be alive.

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.

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.