Leukemia, the most common type of childhood cancer, is a cancer of the bone marrow and blood. When a child has leukemia, his or her bone marrow makes white blood cells that do not mature properly. These unhealthy cells rapidly reproduce, crowding out the healthy bone marrow cells that produce infection-fighting white blood cells, red blood cells and platelets. Leukemia can occur at any age, but is most commonly seen in children between 2 and 6 years old. Little is known about the cause of most leukemia and it typically affects otherwise healthy children. Some children with certain genetic syndromes are at a higher risk of developing the disease.
The major types of childhood leukemia include:
- Acute lymphoblastic leukemia (ALL), also known as acute lymphoid leukemia
- Acute myeloid leukemia (AML)
- Myelodysplastic syndrome (MDS)
- Chronic myeloid leukemia (CML)
- Juvenile myelomonocytic leukemia (JMML)