Childhood Acute Lymphoblastic Leukemia Treatment (PDQ®)–Patient Version

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General Information About Childhood Acute Lymphoblastic Leukemia

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Childhood acute lymphoblastic leukemia (ALL) is a type of cancer in which the bone marrow makes too many immature lymphocytes (a type of white blood cell).
Leukemia may affect red blood cells, white blood cells, and platelets.
Past treatment for cancer and certain genetic conditions affect the risk of having childhood ALL.
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 immature lymphocytes (a type of white blood cell).

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

Anatomy of the bone; drawing shows spongy bone, red marrow, and yellow marrow. A cross section of the bone shows compact bone and blood vessels in the bone marrow. Also shown are red blood cells, white blood cells, platelets, and a blood stem cell. — Anatomy of the bone. The bone is made up of compact bone, spongy bone, and bone marrow. Compact bone makes up the outer layer of the bone. Spongy bone is found mostly at the ends of bones and contains red marrow. Bone marrow is found in the center of most bones and has many blood vessels. There are two types of bone marrow: red and yellow. Red marrow contains blood stem cells that can become red blood cells, white blood cells, or platelets. Yellow marrow is made mostly of fat.

ALL is the most common type of cancer in children.

Leukemia may affect red blood cells, white blood cells, and platelets.

In a healthy child, the bone marrow makes blood stem cells (immature cells) that become mature blood cells over time. A blood stem cell may become a myeloid stem cell or alymphoid stem cell.

A myeloid stem cell becomes one of three types of mature blood cells:

Red blood cells that carry oxygen and other substances to all tissues of the body.
Platelets that form blood clots to stop bleeding.
White blood cells that fight infection and disease.

A lymphoid stem cell becomes a lymphoblast cell and then one of three types oflymphocytes (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.

Blood cell development; drawing shows the steps a blood stem cell goes through to become a red blood cell, platelet, or white blood cell. A myeloid stem cell becomes a red blood cell, a platelet, or a myeloblast, which then becomes a granulocyte (the types of granulocytes are eosinophils, basophils, and neutrophils). A lymphoid stem cell becomes a lymphoblast and then becomes a B-lymphocyte, T-lymphocyte, or natural killer cell. — Blood cell development. A blood stem cell goes through several steps to become a red blood cell, platelet, or white blood cell.

In a child with ALL, too many stem cells become lymphoblasts, B lymphocytes, or T lymphocytes. These cells are cancer (leukemia) cells. The leukemia cells do not work like normal lymphocytes and are not able to fight infection very well. Also, as the number of leukemia cells 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 in children, adolescents, and young adults. See the following PDQ summaries for information about other types of leukemia:

Past treatment for cancer and certain genetic conditions affect the risk of having 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. Talk with your child's doctor if you think your child may be at risk.

Possible risk factors for ALL include the following:

Being exposed to x-rays before birth.
Being exposed to radiation.
Past treatment with chemotherapy.
Having certain changes in the chromosomes or genes.
Having certain genetic conditions, such as:
- Down syndrome.
- Neurofibromatosis type 1 (NF1).
- Shwachman syndrome.
- Bloom syndrome.
- Ataxia-telangiectasia.

Signs of childhood ALL include fever and bruising.

These and other signs and symptoms may be caused by childhood ALL or by other conditions. Check with your child's doctor if your child has any of the following:

Fever.
Easy bruising or bleeding.
Petechiae (flat, pinpoint, dark-red 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, feeling tired, or looking pale.
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 to diagnose childhood ALL and find out if leukemia cells have spread to other parts of the body such as the brain or testicles:

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.
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.
Bone marrow aspiration and biopsy : The removal of bone marrow and a small piece of bone by inserting a hollow needle into the hipbone or breastbone. A pathologistviews the bone marrow 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 bone marrow needle is inserted into the child’s hip bone. Samples of blood, bone, and bone marrow are removed for examination under a microscope.
The following tests may be done on the tissue that is removed:
- 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 of lymphocytes. For example, in Philadelphia chromosome –positive ALL, part of one chromosome switches places with part of another chromosome. This is called the “Philadelphia chromosome.”
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  Philadelphia chromosome. A piece of chromosome 9 and a piece of chromosome 22 break off and trade places. The bcr-abl gene is formed on chromosome 22 where the piece of chromosome 9 attaches. The changed chromosome 22 is called the Philadelphia chromosome.
- Immunophenotyping : A laboratory test in which the antigens or markers on the surface of a blood or bone marrow cell are checked to see if they are lymphocytes or myeloid cells. If the cells are malignant lymphocytes (cancer) they are checked to see if they are B lymphocytes or T lymphocytes.
Lumbar puncture : A procedure used to collect a sample of cerebrospinal fluid (CSF) from the spinal column. This is done by placing a needle between two bones in thespine and into the CSF around the spinal cord and removing a sample of the fluid. The sample of CSF is checked under a microscope for signs that leukemia cells have spread to the brain and spinal cord. This procedure is also called an LP or spinal tap.
ENLARGE
Lumbar puncture. A patient lies in a curled position on a table. After a small area on the lower back is numbed, a spinal needle (a long, thin needle) is inserted into the lower part of the spinal column to remove cerebrospinal fluid (CSF, shown in blue). The fluid may be sent to a laboratory for testing.
This procedure is done after leukemia is diagnosed to find out if leukemia cells have spread to the brain and spinal cord. Intrathecal chemotherapy is given after the sample of fluid is removed to treat any leukemia cells that may have spread to the brain and spinal cord.
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. The chest x-ray is done to see if leukemia cells have formed a mass in the middle of the chest.
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.

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

The prognosis (chance of recovery) depends on:

Age at diagnosis, gender, and race.
The number of white blood cells in the blood at diagnosis.
Whether the leukemia cells began from B lymphocytes or T lymphocytes.
Whether there are certain changes in the chromosomes or genes of the lymphocytes with cancer.
Whether the child has Down syndrome.
Whether leukemia cells are found in the cerebrospinal fluid.
Weight at diagnosis and during treatment.
How quickly and how low the leukemia cell count drops after the first or second phase of treatment.

Treatment options depend on:

Whether the leukemia cells began from B lymphocytes or T lymphocytes.
Whether the child has standard-risk or high-risk ALL.
The age of the child at diagnosis.
Whether there are certain changes in the chromosomes of lymphocytes, such as the Philadelphia chromosome.
How quickly and how low the leukemia cell count drops after initial treatment.

For leukemia that relapses (comes back) after initial treatment, the prognosis and treatment options depend partly on the following:

How long it is between diagnosis and when the leukemia comes back after initial treatment.
Whether the leukemia comes back in the bone marrow or in other parts of the body.

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Risk Groups for Childhood Acute Lymphoblastic Leukemia