Childhood cancers: leukemia

This is the most frequent form of cancer in children: almost one in three cancers occurring in children is leukemia.

Leukemia originates in the bone marrow, in the immature cells that are a precursor to the formation of the various blood cells: white blood cells, red blood cells and platelets. There are different forms of leukemia according to the cell type involved.

With around 85% of cases, lymphoblastic leukemia is the most common form in children. Much more rarely, children can develop myeloblastic leukemia.

One of the specific features of leukemia is that it affects the entire body. Since leukemia develops and damages the precursor blood cells after invading the bone marrow, the tumor cells may then be found wherever the blood flows, and can even spread to certain organs.
Treatment largely involves chemotherapy, or more exactly the combination of several chemotherapy molecules. It may also involve radiotherapy when the cancer has spread to sites that could benefit from this method of treatment. A bone marrow transplant may also be offered. This transplant replaces the bone marrow damaged by the disease or by the treatments.

Chemotherapy may in fact cause the destruction of part of the cells of the bone marrow. Children may suffer periods of aplasia due to the decreased production of blood cells. They are therefore very sensitive to infection.