What is leukemia?

Leukemia is cancer of the blood. It starts in the bone marrow where blood cells are made. Bone marrow is found in the soft, spongy center of the long bones of the arms and legs.

Healthy marrow makes three types of blood cells:

  • White blood cells that fight infections
  • Red blood cells that carry oxygen
  • Platelets that make the blood clot to stop bleeding

In childhood leukemia, some blood cells don't develop correctly. Instead, there are too many underdeveloped cells in the blood and bone marrow. These cells crowd out normal, healthy blood cells that the body needs.

There are several types of leukemia. The most common type in children is acute lymphocytic leukemia (ALL). In fact, this is the most common of all childhood cancers.

Childhood Leukemia

Any child can get leukemia. Doctors do not know what causes the disease. There are several factors that may increase a child's risk, but most children who have leukemia have none of these risk factors.

For example, children who were exposed to chemicals such as benzene are at greater risk for acute myelogenous leukemia (AML) than children who were not exposed. This is a risk factor. Most children develop the disease for unknown reasons.

Leukemia at Seattle Children's

Leukemia affects more children than any other type of cancer. If your child has leukemia, you are not alone. Many other families have faced childhood leukemia, too. Many of them have made it through this difficult time with treatment and support from Seattle Children's Hospital. The experts in our Leukemia and Lymphoma Program provide advanced therapies for children with leukemia that's newly diagnosed, as well as those with recurrent or relapsed leukemia.

Seattle Children's takes part in clinical trials to treat and, we hope someday, to cure leukemia.

Each year we treat 60-70 children who have been newly diagnosed with this type of cancer. These include Phase I and Phase II trials to test T-cell therapy, a type of immunotherapy, in children and young adults with ALL.

We provide comprehensive care - from child life services and nutrition support, to new medicine studies and hematopoietic cell transplants through our partnership with Fred Hutch, whose doctors pioneered these transplants.

Childhood leukemia survival rates

Doctors who treat people with cancer use five-year survival rates as a way to measure treatment success. The five-year survival rate means the percentage of patients with the disease who are alive five years after their disease was diagnosed.

For ALL our survival rate is 13.5 points higher than the national average. For AML our rate is 3.5 points higher than the national average. Read more childhood cancer statistics.