Childhood Leukemia

In the 1950's, nearly every child diagnosed with leukemia died within six months. But today there is hope for children with leukemia, thanks to biomedical research using animals, which has made new developments in leukemia treatment possible. There are now advanced cancer centers which treat leukemia with bone marrow transplants. Today, about 75% of the children diagnosed each year with leukemia will be cured of their disease and be able to live healthy and productive lives.

About 4% of all cancers are leukemias, or blood cancers. Leukemia is characterized by an abnormal number of white blood cells produced by the bone marrow. This disease kills more children between the ages of 2 and 15 than any other disease. More than 25,000 new cases of leukemia are diagnosed in children each year in North America.

Specifically, leukemia is a malignancy of the blood-forming tissues of the body. The bone marrow, the lymphatic tissues, the spleen, some connective tissues, and some lymph nodes produce immature white blood cells, or leukocytes.

In leukemia, millions of immature and useless white blood cells are produced and the bloodstream is flooded with these useless cells, called blasts. They accumulate in the blood and in the bone marrow, and eventually the bone marrow is replaced by these abnormal cells. When this happens, the bone marrow cannot produce the normal blood cells that the body needs (platelets, red cells and mature white cells).

Bone marrow transplants were introduced as a treatment for leukemic children in the 1970s, for use when drug treatment does not work. At least one-third of all leukemia patients have a brother or sister whose bone marrow can be used in a transplant operation.

In a newer approach, some of the patient's own bone marrow is removed while he or she is in remission, stored in a freezer, and re-transplanted later if a relapse occurs.

More than 10,000 bone marrow transplants have now been performed worldwide. For most forms of childhood leukemia, a remission that lasts five years following treatment is now considered a cure.