Leukemia

The term leukemia refers to cancers of the white blood cells (also called leukocytes or WBCs). Leukemias, as a group, make up about a quarter of all pediatric cancers. Luckily, with treatment, most children with leukemia will be free of the disease without it coming back.

Leukemias start in the bone marrow — the soft tissue found inside bones that produces blood cells. When a child is diagnosed with leukemia, it’s because the white blood cells in the body are producing abnormally. These cells (also known as blasts) start to crowd out the healthy cells in the bone marrow. Eventually, the healthy cells have no place to go, so they stop producing. When a child's body no longer produces enough healthy white blood cells it can cause anemia, swollen lymph nodes, and other symptoms of leukemia in children.

Leukemia is classified as being either acute (meaning it’s rapidly developing) or chronic (meaning it’s slowly developing). About 98% of pediatric leukemias are acute.

 
Types of Pediatric Leukemia
Types of leukemia in children include:
  • Acute lymphoblastic leukemia (ALL): This happens when too many lymphoblasts (a certain type of white blood cell) are produced.
    This is the most common type of leukemia, affecting nearly 60% of kids with leukemia.
  • Acute myelogenous leukemia (AML): This occurs when too many immature white blood cells (called myeloid blasts) are made.
    These leukemia cells are abnormal and can’t mature into normal white blood cells.
  • Chronic myelogenous leukemia (CML): This rare form of pediatric leukemia happens because there are too many mature white blood cells.

 
Signs and Symptoms of Leukemia in Children

Although the symptoms of leukemia in each individual child can vary, common symptoms of leukemia in children include:

  • anemia  (when the level of healthy red blood cells in the body becomes
    too low)
  • bleeding and/or bruising
  • frequent or reoccurring infections
  • bone and joint pain
  • abdominal pain
  • swollen lymph nodes (also called “swollen glands”)
  • difficulty breathing
  • excessive fatigue (more tired than usual)
  • poor appetite

IMPORTANT NOTE: Instances of the symptoms of leukemia in children listed above, either together or on their own, do not automatically mean that a child has leukemia or any other kind of cancer. Any or all of these symptoms could be a sign of something else.

 
Diagnosing Leukemia in Children

One of our Nemours pediatric hematologists-oncologists (doctors who treat blood disorders and cancers) will conduct a physical examination on your child to check for symptoms of leukemia in children such as signs of infection, anemia, abnormal bleeding, and swollen lymph nodes.

The doctor will also feel your child's abdomen to see if the liver or spleen is enlarged. We’ll also take a complete medical history by asking about your child’s symptoms, past health, your family's health history, any medications your child is taking, allergies, etc.

After this exam, the doctor will order a CBC (complete blood count) to measure the numbers of white cells, red cells, and platelets in your child's blood. Your child’s blood chemistries will also be checked.

Then, depending on what we find in the exam and blood tests, your child also may need a:

  • bone marrow biopsy and aspiration (when marrow samples are taken for testing, usually from the back of the hip)
  • lymph node biopsy (when lymph nodes are removed and examined under a microscope to look for abnormal cells)
  • lumbar puncture (also called a spinal tap, when a sample of spinal fluid is taken from the lower back and examined for evidence of abnormal cells. This test will show if the leukemia has spread to the brain and spinal cord.)

We know that tests can be scary – for you and your child. Whatever kind of tests your child might need, know that your Nemours pediatric leukemia care team will do everything we can to make the experience as comfortable as possible – physically and emotionally. We’ll give sedation or anesthesia as needed and offer support and guidance at every step.

Learn more about what to expect with certain medical tests »

 
Treating Leukemia in Children

Depending on your child’s age, overall health, extent of the disease, and other factors, treatment may include one or a combination of the following:

  • chemotherapy
  • radiation therapy   
  • blood or bone marrow transplant (also sometimes called a BMT, BBMT, stem cell transplant, or cord blood transplant)
  • medications/antibiotics
  • blood transfusions

At Nemours, we know that getting a cancer diagnosis can be very frightening and overwhelming for your whole family. That’s why Nemours’ board-certified pediatric hematologists-oncologists, specialty nurses, cancer researchers, and other cancer experts are focused on helping not only your child, but your family, as well.

From diagnosis to treatment (and beyond) we’ll be here to help guide your family through your pediatric leukemia journey – and to strive and hope, with you, for a better tomorrow.

Leukemia

(Cáncer infantil: Leucemia)

About Leukemia

The term leukemia refers to cancers of the white blood cells (also called leukocytes or WBCs). When a child has leukemia, large numbers of abnormal white blood cells are produced in the bone marrow. These abnormal white cells crowd the bone marrow and flood the bloodstream, but they cannot perform their proper role of protecting the body against disease because they are defective.

As leukemia progresses, the cancer interferes with the body's production of other types of blood cells, including red blood cells and platelets. This results in anemia (low numbers of red cells) and bleeding problems, in addition to the increased risk of infection caused by white cell abnormalities.

As a group, leukemias account for about 25% of all childhood cancers and affect about 2,200 American young people each year. Luckily, the chances for a cure are very good with leukemia. With treatment, most children with leukemia will be free of the disease without it coming back.

Types of Leukemia

In general, leukemias are classified into acute (rapidly developing) and chronic (slowly developing) forms. In children, about 98% of leukemias are acute.

Acute childhood leukemias are also divided into acute lymphocytic leukemia (ALL) and acute myelogenous leukemia (AML), depending on whether specific white blood cells called lymphyocytes (or myelocytes), which are linked to immune defenses, are involved.

Approximately 60% of children with leukemia have ALL, and about 38% have AML. Although slow-growing chronic myelogenous leukemia (CML) may also be seen in children, it is very rare, accounting for fewer than 50 cases of childhood leukemia each year in the United States.

Causes

The ALL form of the disease most commonly occurs in younger children ages 2 to 8, with a peak incidence at age 4. But it can affect all age groups.

Kids have a 20% to 25% chance of developing ALL or AML if they have an identical twin who was diagnosed with the illness before age 6. In general, nonidentical twins and other siblings of children with leukemia have two to four times the average risk of developing this illness.

Children who have inherited certain genetic problems — such as Li-Fraumeni syndrome, Down syndrome, Kleinfelter syndrome, neurofibromatosis, ataxia telangectasia, or Fanconi's anemia — have a higher risk of developing leukemia, as do kids who are receiving medical drugs to suppress their immune systems after organ transplants.

Children who have received prior radiation or chemotherapy for other types of cancer also have a higher risk for leukemia, usually within the first 8 years after treatment.

In most cases, neither parents nor kids have control over the factors that trigger leukemia, although current studies are investigating the possibility that some environmental factors may increase the risk that a child will develop the disease. Most leukemias arise from noninherited mutations (changes) in the genes of growing blood cells. Because these errors occur randomly and unpredictably, there is currently no effective way to prevent most types of leukemia.

To limit the risk of prenatal radiation exposure as a trigger for leukemia (especially ALL), women who are pregnant or who suspect that they might be pregnant should always inform their doctors before undergoing tests or medical procedures that involve radiation (such as X-rays).

Regular checkups can spot early symptoms of leukemia in the relatively rare cases where this cancer is linked to an inherited genetic problem, to prior cancer treatment, or to use of immunosuppressive drugs for organ transplants.

Symptoms

Because their infection-fighting white blood cells are defective, kids with leukemia may experience increased episodes of fevers and infections. They also may become anemic, because leukemia affects the bone marrow's production of oxygen-carrying red blood cells. This makes them appear pale, and they may become abnormally tired and short of breath while playing.

Children with leukemia might bruise and bleed very easily, experience frequent nosebleeds, or bleed for an unusually long time after even a minor cut because leukemia destroys the bone marrow's ability to produce clot-forming platelets.

Other symptoms of leukemia can include:

  • pain in the bones or joints, sometimes causing a limp
  • swollen lymph nodes (sometimes called swollen glands) in the neck, groin, or elsewhere
  • an abnormally tired feeling
  • poor appetite

In about 12% of kids with AML and 6% of those with ALL, spread of leukemia to the brain causes headaches, seizures, balance problems, or abnormal vision. If ALL spreads to the lymph nodes inside the chest, the enlarged gland can crowd the trachea (windpipe) and important blood vessels, leading to breathing problems and interference with blood flow to and from the heart.

Diagnosis

Your child's doctor will perform a physical examination to check for signs of infection, anemia, abnormal bleeding, and swollen lymph nodes. The doctor will also feel your child's abdomen to see if there is an enlarged liver or spleen because they can become enlarged with some cancers in children.

In addition to doing a physical exam, the doctor will take a medical history by asking you about symptoms, past health, your family's health history, medications your child is taking, allergies, and other issues.

After this exam, the doctor will order a CBC (complete blood count) to measure the numbers of white cells, red cells, and platelets in your child's blood. A blood smear will be examined under a microscope to check for certain specific types of abnormal blood cells usually seen in patients with leukemia. Blood chemistries will also be checked.

Then, depending on the results of the physical exam and preliminary blood tests, your child may need:

  • a bone marrow biopsy and aspiration, in which marrow samples are removed (usually from the back of the hip) for testing
  • a lymph node biopsy, in which lymph nodes are removed and examined under a microscope to look for abnormal cells
  • a lumbar puncture (spinal tap), where a sample of spinal fluid is removed from the lower back and examined for evidence of abnormal cells. This will show whether the leukemia has spread to the central nervous system (brain and spinal cord).

Bone marrow or lymph node samples will be examined and additional testing done to determine the specific type of leukemia. In addition to these basic lab tests, cell evaluations might be done, including genetic studies to distinguish between specific types of leukemia and certain features of the leukemia cells. Kids will receive anesthesia or sedative medications for any painful procedures.

Treatment

Certain features of a child's leukemia, such as age and initial white blood cell count, are used in determining the intensity of treatment needed to achieve the best chance for cure. Although all kids with ALL are treated with chemotherapy, the dosages and drug combinations may differ.

To decrease the chance that leukemia will invade the child's central nervous system, patients receive intrathecal chemotherapy, the administration of cancer-killing drugs into the cerebrospinal fluid around the brain and spinal cord.

Radiation treatments, which use high-energy rays to shrink tumors and keep cancer cells from growing, may be used in addition to intrathecal chemotherapy for certain high-risk patients. Children then require continued close monitoring by a pediatric oncologist, a specialist in childhood cancer.

After treatment begins, the goal is remission of the leukemia (when there is no longer evidence of cancer cells in the body). Once remission has occurred, maintenance chemotherapy is usually used to keep the child in remission. Maintenance chemotherapy is given in cycles over a period of 2 to 3 years to keep the cancer from returning. Leukemia will almost always relapse (reoccur) if this additional chemotherapy isn't given. Sometimes the cancer will return in spite of maintenance chemotherapy, and other forms of chemotherapy will then be necessary.

Sometimes a bone marrow transplant may be necessary in addition to — or instead of — chemotherapy, depending on the type of leukemia a child has. During a bone marrow transplant, healthy bone marrow is introduced into a child's body.

Intensive leukemia chemotherapy has certain side effects, including hair loss, nausea and vomiting, and increased risk for infection or bleeding in the short term, as well as other potential health problems down the line. As your child is treated for leukemia, the cancer treatment team will watch closely for those side effects.

But with the proper treatment, the outlook for kids who are diagnosed with leukemia is quite good. Some forms of childhood leukemia have a remission rate of up to 90%; all kids then require regular maintenance chemotherapy and other treatment to continue to be cancer-free. Overall cure rates differ depending on the specific features of a child's disease. Most childhood leukemias have very high remission rates. And the majority of kids can be cured (meaning that they are in permanent remission) of the disease.

Reviewed by: Robin E. Miller, MD
Date reviewed: September 2010