Leukemia is cancer of the blood and bone marrow, the spongy center of bones where our blood cells are formed. Leukemia developing in the lymphocytes (lymphoid cells) is called lymphocytic leukemia. Leukemia developing in the granulocytes or monocytes or myeloid cells is called myelogenous leukemia. Acute leukemias (either lymphocytic or myelogenous) involve new or immature cells (or blasts) that remain immature and incapable of performing their functions. The blasts increase in number rapidly, and the disease progresses quickly. Chronic leukemias involve some blast cells, but they are more mature and are able to perform some of their functions. The cells tend to grow more slowly and the number increases less quickly, so the disease progresses gradually.
Acute lymphocytic leukemia (ALL) is a rapidly progressing disease in which too many immature lymphocytes (type of white blood cell) are produced in the bone marrow. It is the most common cancer diagnosed in children, with approximately 2,900 children and teens diagnosed each year in America. Incidence of ALL is highest among children ages two to three years, among whom rates are about four times higher than for children ages eight to ten years.
One of the most serious potential long-term side effects of ALL therapy is the development of AML. This occurs in about 5% of patients after they have received chemotherapy drugs called epipodophyllotoxins (e.g., etoposide or teniposide) or alkylating agents (e.g., cyclophosphamide or chlorambucil). Less often, children cured of leukemia may later develop non-Hodgkin lymphomas or other cancers. Among children with ALL, more than 95% attain remission and 75%-85% are free of recurrence for at least 5 years after diagnosis.
There is a wide range of potential symptoms of leukemia, including: easy bruising or blood with no clear cause (due to low platelet count); pinhead size red spots under the skin; cuts that take a long time to heal; fatigue or chronic lack of energy and paleness (due to enema); shortness of breath during normal physical activity; mild fever; night sweats; swollen gums; frequent minor infections (due to low white blood cell count); unexplained weight loss; chronic aches or discomfort in bones or joints; and pain or discomfort in the upper left part of the stomach (caused by an enlarged spleen).
Chemotherapy is the standard treatment for AML. Some patients may also receive radiation therapy or a bone-marrow transplant using their own or a closely related sibling’s cells. Treatment in adults has two phases. The first, called induction, is designed to clear the blood of leukemia cells and put the disease into remission. Induction usually kills most cancer cells. The goal of the second phase, called consolidation, is to kill any remaining leukemia cells.