Leukemia in Children and Young Adults

The most common type of cancer in children is leukemia. There are different types of leukemia, and the two that most often occur in children are acute lymphocytic leukemia (ALL) and acute myeloid leukemia (AML). Both ALL and AML are fast-growing cancers and treatment is needed to stop the cancer from growing, but these types of leukemia generally respond well to treatment. Although rare, Chronic myeloid leukemia can also occur in children.

About leukemia

Leukemia is a cancer in which the white blood cells (WBCs) abnormally multiply in the bone marrow and blood. The large number of irregular WBCs do not fight infection properly, and they can disrupt the formation of red blood cells and platelets.1,2

Leukemias are named for the type of white blood cell that they develop from. Lymphocytic leukemias develop from the immature lymphoid cells, which can become B cells, T cells, and natural killer cells. Myeloid leukemias (also called myelogenous leukemias or myelocytic leukemias) develop from immature myeloid cells, which can become white blood cells, red blood cells, and platelets.1,2

Leukemias are also classified as acute or chronic. Acute leukemias are fast-growing and can progress quickly if not treated, however, they generally respond well to treatment. Chronic leukemias are slower growing, but they can sometimes be harder to treat. Almost all leukemias that occur in children are acute. Rarely, a child can develop a chronic leukemia.1,2

About acute lymphocytic leukemia

Approximately 3 out of 4 childhood leukemias are classified as ALL. The risk of ALL is greatest in children younger than 5 years of age and is most commonly diagnosed between the ages 2 and 4.1

ALL develops from the lymphoid cells, which normally become B cells, T cells, and natural killer cells. ALL can be divided into subtypes including B cell leukemia and T cell leukemia.3

About acute myeloid leukemia

Most of the remaining cases of leukemia that occur in children are classified as AML. AML can develop in children of any age, but it is most common during the first 2 years of life or during the teen years.1

AML develops from myeloid cells, which normally develop into white blood cells, red blood cells, and platelets. AML can be further categorized into multiple subtypes.1,3

How is leukemia staged in children?

Childhood AML does not have a standard staging system and is generally classified by its subtype, which can help to guide treatment recommendations. Childhood ALL is also usually classified by its subtype. B cell ALL and T cell ALL are the two main subtypes, named for the type of white blood cell they develop from.1,4

What is the prognosis of childhood leukemia?

The prognosis, or expected outcome, depends on many factors, including:

  • How quickly the leukemia responds to treatment – Those whose leukemia responds relatively quickly generally have a better outcome.
  • The age of the child – In ALL, children between the ages of 1 and 9 with B-cell ALL tend to have a higher rate of cure. In AML, children younger than age 2 may have a better outcome than older children, but age tends to not be a major factor in the prognosis of childhood AML.
  • The number of white blood cells at diagnosis – For ALL, children who have a count of more than 50,000 cells per cubic millimeter at diagnosis may need increasingly intense treatment. For AML, a count of less than 100,000 cells per cubic millimeter at diagnosis tend to be cured more frequently than patients with higher white blood cell counts at diagnosis.
  • The subtype of leukemia – There are differences between the subtypes of ALL and AML, with some subtypes having more favorable outlooks than others.
  • Ethnicity of the child – Children of African American or Hispanic backgrounds tend to have a lower cure rate than children from other ethnicities.1

Overall, the survival rate for childhood leukemia has been steadily increasing over the last few decades. Survival rates are based on past data of people who survive a set amount of time after diagnosis. In cancer estimates, experts use the “five-year survival rate” as a marker. However, it is important to keep in mind that many people live beyond five years after diagnosis and the statistics are not necessarily predictive for any one individual. The five-year survival rate for ALL in children is more than 85%, and the five-year survival rate for AML in children is between 60-70%. Chronic myeloid leukemia, which is rare in children, has previously had a five-year survival rate of 60-80%, although newer, more effective treatments that are now available may have not yet impacted these numbers.1

Written by: Emily Downward | Last reviewed: February 2018
View References
  1. American Cancer Society. Available at https://www.cancer.org/. Accessed 12/8/17.
  2. American Society of Hematology. Available at http://www.hematology.org/Patients/Cancers/. Accessed on 9/6/17.
  3. Leukemia & Lymphoma Society. Available at http://www.lls.org/. Accessed 12/8/17.
  4. National Cancer Institute. Available at https://www.cancer.gov/types/leukemia/patient/child-aml-treatment-pdq. Accessed 2/21/18.