LEUKEMIA - ACUTE MYELOGENOUS (AML)-CHILD

Acute myelogeous (or myeloid) leukemia (AML) is a malignancy of what is called the 'hematopoietic system' – that is, the bone marrow-based cellular apparatus which gives rise to the various different blood cells. Specifically, AML is a malignancy involving the progenitors (precursors) of the myeloid cells, which are the cells that give rise to non-lymphocytic white blood cells. For this reason, it is occasionally referred to as acute non-lymphocytic leukemia (ANLL).

Non-lymphocytic white cells include the neutrophils (which are the frontline against bacterial infection), the monocytes (which are bastions of the immune system), and eosinophils and basophils, which are also part of the immune system, particularly that part concerned with allergy and reaction to tissue damage.

AML is defined by the presence in the blood and bone marrow of large numbers of malignant primitive forms of blood cells (called 'blasts') whose development is arrested at an early stage. Vast numbers of these leukemic blast cells accumulate in the bone marrow cavity and then in the blood, crowding out the normal cells and interfering with with the normal functioning of the blood and bone marrow.

Pediatric AML is a rare disease. In fact, it afflicts about 400 children under the age of 15 per year in the US, with a total of 550 under the age of 21. This amounts to an incidence of about just 6 per million US children.

While there have been great strides in treatment of childhood leukemias as a whole, progress has on the whole been slower in AML than it has in ALL. Throughout the 1990s the average 5-year survival remained around 50 percent. Curiously, the outcome for girls with AML tends to be slightly more favorable on average than it does for boys.