Reviewed by health care specialists at UCSF Medical Center.


Leukemia is cancer of the body’s blood-forming tissues, including the bone marrow and lymph system. When this condition occurs, bone marrow produces a large number of abnormal white blood cells — or, in some cases, a large number of red blood cells or platelets.

Normal white blood cells are potent infection fighters. But in people with leukemia, abnormal white blood cells tend to accumulate, blocking production of normal white blood cells and impairing the ability to fight infection.

Treatment for leukemia is complex. Most patients are treated with chemotherapy. Some also may have radiation therapy, a blood or marrow transplant (BMT) or biological therapy.

Many people believe leukemia only affects children, but roughly 10 times as many adults as children are diagnosed with this cancer. New cases of leukemia number nearly 30,000 annually in the United States.