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Understanding childhood leukemia

A smiling child wearing a head scarf hugs a stuffed animal.

A look at the causes of childhood leukemia and treatments that can help put the disease into remission.

Leukemia is the most common form of childhood cancer. It's a serious diagnosis—but a treatable one. In fact, most of the kids who develop this disease will survive for at least five years and probably longer, reports the American Cancer Society (ACS).

How leukemia occurs

Leukemia is a cancer of stem cells. These cells live in the bone marrow and, in a healthy person, they mature into white blood cells, red blood cells and platelets. Leukemia happens when white blood cells don't mature but instead multiply rapidly and accumulate in the marrow. As more leukemia cells develop, there is less room for healthy blood cells and platelets.

These cancerous cells spread from the bone marrow to the blood. They also can go to other parts of the body such as the lymph nodes, liver, brain and spinal cord.

Most childhood leukemia occurs without any known cause. However, children with risk factors, such as having radiation therapy for other cancers or taking immunosuppressant drugs after organ transplant, are more likely to develop leukemia.

Types of childhood leukemia

Almost all leukemia in children is acute, which means it develops rapidly. Chronic leukemia, which develops slowly over several years, is rare in children.

When acute leukemia involves blood cells called lymphocytes, it's called acute lymphocytic leukemia (ALL) or acute lymphoblastic leukemia. About three out of four children with leukemia have ALL, reports the ACS.

Acute leukemia also can start from cells called myeloid cells. This type is called acute myeloid leukemia (AML). Other names for this form of leukemia include acute myelogenous leukemia, acute myeloblastic leukemia, acute granulocytic leukemia and acute nonlymphocytic leukemia.

Leukemias are also divided into subgroups based on more specific types of cells involved. For example, ALL can be classified as B-cell or T-cell ALL. Knowing the patient's subgroup helps doctors determine the appropriate treatment.


The lack of normal blood cells causes many of the signs and symptoms of leukemia. Others happen if the cancer has invaded other areas of the body.

According to the National Cancer Institute (NCI) and other medical experts, a child with leukemia may have:

  • Fatigue.
  • Pale skin from a shortage of red blood cells.
  • Fever. Leukemia can weaken the immune system and make children vulnerable to infection.
  • Easy bruising or bleeding.
  • Bone or joint pain. This happens from the buildup of leukemia cells inside the bone or joint.
  • Weight loss or poor appetite. Leukemia can cause an enlarged spleen or liver, which can press against the stomach.
  • Swollen lymph nodes.
  • Coughing or trouble breathing due to too many white blood cells in the lungs.

Diagnosing childhood leukemia

The first test for a child with leukemia symptoms is likely to be a complete blood count to examine the blood cells. If this shows abnormal cells, the child may have other tests such as:

  • Bone marrow aspiration and biopsy. A hollow needle is inserted into the hipbone or breastbone to remove bone marrow, blood and a small piece of bone. These samples will be examined for leukemia cells.
  • Imaging tests such as x-rays, CT scans or MRI scans. These look for enlarged lymph nodes or organs to determine the extent of the disease.
  • A spinal tap to check for leukemia cells in the spinal fluid.

How is it treated?

Treatment for childhood leukemia depends on the type of leukemia and factors such as the age of the child and whether the abnormal cells have spread. It is intended to put the disease into remission—a stage in which the blood is almost normal and there are no symptoms—and then kill any remaining cancer cells that could cause a relapse.

According to the NCI, leukemia treatment may include:

Stem cell transplant. Immature blood cells, called stem cells, are removed from blood or bone marrow of the patient or a donor. After chemotherapy, the cells are reintroduced into the patient, where they grow into and restore the body's blood cells.

Targeted therapy. Drugs or other substances are used to spot and attack specific cancer cells without harming normal cells. For example, one type blocks the enzyme that triggers the overproduction.

What is the outlook?

The outlook for a child who has leukemia depends on many factors. However, according to the ACS, most children today survive the disease.

Reviewed 11/11/2022

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