1. What is acute lymphoblastic leukemia (ALL)?

   Acute lymphoblastic leukemia (ALL) is a cancer of the white blood cells, the cells in the body that normally fight infections. There are two main types of white blood cells—lymphoid cells and myeloid cells. ALL affects lymphoid cells.

   Leukemia cells are abnormal cells that cannot do what normal blood cells do. The abnormal cells are immature white blood cells that cannot help the body fight infections. For this reason, children with ALL often get infections and have fevers.

   ALL is also called acute lymphocytic leukemia. It is the most common leukemia in children.

2. What are the symptoms of ALL?

   Like all blood cells, leukemia cells travel through the body. Depending on the number of abnormal cells and where these cells collect, patients with leukemia may have a number of symptoms. Children with ALL frequently have low amounts of healthy red blood cells and platelets. As a result, there are not enough red blood cells to carry oxygen through the body. With this condition, called anemia, patients may look pale and feel weak and tired. When there are not enough platelets, patients bleed and bruise easily.

   Some of the common symptoms of ALL include:

   • fever
     
   • fatigue
     
   • frequent infections
     
   • swollen or tender lymph nodes, liver, or spleen
     
   • paleness or pallor
     
   • easy bleeding or bruising
     
   • tiny red spots (called petechiae) under the skin
     
   • bone or joint pain
     

   In ALL, the abnormal cells may collect in the brain or spinal cord, also called the central nervous system (CNS). The result may be headaches with or without vomiting, although most children with the disease do not have these symptoms. Leukemia cells also can collect in the testicles and cause swelling.

3. Is there a screening test for ALL?

   No. Screening is a means of detecting disease in people who have no symptoms. As described in the National Cancer Institute's Cancer Screening Overview (PDQ®) (http://www.cancer.gov/cancertopics/pdq/screening/overview/healthprofessional), two requirements must be met for screening to be useful:

   (1) There must be a test or procedure that will detect cancers earlier than if the cancer were detected as a result of the development of symptoms, and

   (2) There must be evidence that treatment initiated earlier as a consequence of screening results in an improved outcome.

   These two requirements have not been met for childhood ALL.

   In cancers such as leukemia that appear throughout the body during their earliest stages, screening does not appear to be useful. Rather, children with any symptoms that suggest the possibility of ALL should be seen by their physician. The physician can then examine the child and determine if further testing is needed.

4. How is ALL diagnosed?

   If a child has symptoms that suggest leukemia, the physician may first order blood tests. A sample of blood is examined to determine the number of normal blood cells, to see what the cells look like, and to find out if any leukemia cells are present in the blood. For a definitive diagnosis of ALL, a doctor who specializes in leukemia examines a sample of bone marrow under a microscope. The sample is obtained by a procedure called bone marrow aspiration. In this procedure, the doctor inserts a needle into a large bone, usually the hip, and removes a small amount of liquid bone marrow for examination.

   If leukemia cells are found in the bone marrow sample, the patient's doctor orders other tests to find out the extent of the disease. For example, a spinal tap, which is also called a lumbar puncture, checks for leukemia cells in the cerebrospinal fluid—the fluid that fills the spaces in and around the brain and spinal cord.

5. Are there different types of ALL?

   Although leukemia cells from different children with ALL often look very similar under the microscope, there are actually many distinctive subtypes of ALL. Most cases of leukemia are associated with changes in genes and chromosomes in the cancerous white blood cells. The various subtypes of ALL can be identified using special laboratory tests that look for specific changes in genes and chromosomes. It is increasingly important for doctors treating children with ALL to determine their patients' subtype of ALL, as some treatments work better for some subtypes than for others.

6. How common is ALL?

   Cancer in children and adolescents is rare. But, ALL is the most common cancer in children, representing 23 percent of cancer diagnoses among children younger than 15 years of age. It occurs in about one of every 29,000 children in the United States each year.

7. What causes ALL?

   With the exception of prenatal exposure to X-rays and specific genetic syndromes, such as Down syndrome, little is known about the causes of and risk factors for childhood ALL.

   Scientists know that ALL in children occurs slightly more often in boys than in girls and in white children more often than in black children. However, they cannot explain why one person gets leukemia and another does not.

8. What treatments are available for the disease?

   There are treatments for all children with ALL (see http://www.cancer.gov/cancertopics/pdq/treatment/childALL/healthprofessional). The primary treatment for ALL is chemotherapy. The specific drugs used for chemotherapy are different for the various subtypes of ALL and are not the same for all patients.

   Treatment for children with ALL is complex and involves multiple drugs given in precise schedules over a period of two to three years. Because of this, children with the disease should be treated by doctors with experience and expertise in the treatment of childhood leukemias.

   Many children with ALL participate in clinical trials. These studies test a new drug or a new combination of drugs, often comparing them to the current standard treatment. A participant will usually be assigned to the standard group or the new group by chance, a process called randomization. It is not known at the start of the trial whether the new treatment is better than, the same as, or worse than the standard treatment. Clinical trials for children with ALL often enroll large numbers of children and are conducted at children's cancer centers nationwide. Much of the success in curing children with ALL is the result of better treatments that were identified in such clinical trials. Still, doctors are doing clinical trials to try to improve ALL treatments and reduce side effects.

9. What is the survival rate for children with ALL?

   The improvement in survival for children with ALL over the past 35 years is one of the great success stories of cancer treatment. In the 1960s, less than 5 percent of children with ALL survived for more than five years. Today, about 85 percent of children with ALL live five years or more.

10. What factors determine successful treatment for children with ALL?

    The chance of survival for children with ALL is dependent upon a number of factors. The most important factor is receiving optimal care at a center experienced in the treatment of children with ALL. Even with optimal care, some children with ALL are much more difficult to treat successfully than others.

    In the past, factors such as age and white blood cell count at diagnosis were commonly used to predict outcome. For example, children 1 to 9 years old have higher survival rates than do infants or older children. However, factors such as age and white blood cell count at diagnosis are, at best, crude predictors of outcome.

    It is now clear that the patient's subtype of ALL has a powerful impact on survival. For example, infants commonly have a subtype of ALL in which a specific gene is modified. This subtype of ALL is very hard to treat successfully and only a minority of infants with this subtype of ALL survive with current therapy. Other subtypes of ALL in which different genes are modified occur more commonly in older children and have a much more favorable outcome.

    It is now common practice for the leukemia cells of children with ALL to be tested for the gene modifications. The type of treatment is then based on the particular change seen in the leukemia cells.

    # # #

    
    Related NCI materials and Web pages:
    • National Cancer Institute Fact Sheet 1.21, Care for Children and Adolescents With Cancer ¹
      (http://www.cancer.gov/cancertopics/factsheet/NCI/children-adolescents)
    • National Cancer Institute Fact Sheet 6.40, Childhood Cancers: Questions and Answer ²
      (http://www.cancer.gov/cancertopics/factsheet/Sites-Types/childhood)
    • Taking Part in Cancer Treatment Research Studies ³
      (http://www.cancer.gov/clinicaltrials/Taking-Part-in-Cancer-Treatment-Research-Studies)
    • What You Need To Know About™ Leukemia ⁴
      (http://www.cancer.gov/cancertopics/wyntk/leukemia)
    • Childhood Cancers Home Page ⁵
      (http://www.cancer.gov/cancertopics/types/childhoodcancers)
    • Leukemia Home Page ⁶
      (http://www.cancer.gov/cancertopics/types/leukemia)

    How can we help?

    We offer comprehensive research-based information for patients and their families, health professionals, cancer researchers, advocates, and the public.

    • Call NCI’s Cancer Information Service at 1–800–4–CANCER (1–800–422–6237)
    • Visit us at http://www.cancer.gov or http://www.cancer.gov/espanol
    • Chat using LiveHelp, NCI’s instant messaging service, at http://www.cancer.gov/livehelp
    • E-mail us at cancergovstaff@mail.nih.gov
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Glossary Terms

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

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 ALL.

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

Removal of fluid or tissue through a needle. Also, the accidental breathing in of food or fluid into the lungs.

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

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 a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a 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. Also called malignancy.

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

The brain and spinal cord. Also called CNS.

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.

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.

To heal or restore health; a treatment to restore health.

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

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 condition marked by extreme tiredness and inability to function due lack of energy. Fatigue may be acute or chronic.

An increase in body temperature above normal (98.6 degrees F), usually caused by disease.

The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein.

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

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.

In medicine, the place where two or more bones are connected. Examples include the shoulder, elbow, knee, and jaw.

A medical procedure that involves testing a sample of blood, urine, or other substance from the body. Tests can help determine a diagnosis, plan treatment, check to see if treatment is working, or monitor the disease over time.

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

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 rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph nodes filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. Also called lymph gland.

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

An instrument that is used to look at cells and other small objects that cannot be seen with the eye alone.

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 specific result or effect that can be measured. Examples of outcomes include decreased pain, reduced tumor size, and improvement of disease.

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.

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

Medical doctor.

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.

Initial treatment used to reduce a cancer. Primary treatment 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, induction therapy, and primary therapy.

When referring to an experiment or clinical trial, the process by which animal or human subjects are assigned by chance to separate groups that compare different treatments or other interventions. Randomization gives each participant an equal chance of being assigned to any of the groups.

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

Something that increases the chance of developing a disease. Some examples of risk factors for cancer are age, a family history of certain cancers, use of tobacco products, being exposed to radiation or certain chemicals, infection with certain viruses or bacteria, and certain genetic changes.

A person who has studied science, especially one who is active in a particular field of investigation.

Checking for disease when there are no symptoms. Since screening may find diseases at an early stage, there may be a better chance of curing the disease. Examples of cancer screening tests are the mammogram (breast), colonoscopy (colon), Pap smear (cervix), and PSA blood level and digital rectal exam (prostate). Screening can also include checking for a person’s risk of developing an inherited disease by doing a genetic test.

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.

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 lumbar puncture.

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.

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.

The percentage of people in a study or treatment group who are alive for a certain period of time after they were diagnosed with or treated for a disease, such as cancer. The survival rate is often stated as a five-year survival rate, which is the percentage of people in a study or treatment group who are alive five years after diagnosis or treatment. Also called overall survival rate.

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

A set of symptoms or conditions that occur together and suggest the presence of a certain disease or an increased chance of developing the disease.

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

To eject some or all of the contents of the stomach through the mouth.

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.