is cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of blood cells to be produced and enter the bloodstream. Each year, about 29,000 adults and 2,000 children in the United States are diagnosed with leukemia.
- Acute lymphoblastic leukemia (ALL)
- Acute myelogenous leukemia (AML).
Cancer in children and adolescents is rare. However, childhood acute lymphoblastic leukemia
(ALL) is the most common cancer in children, representing 23 percent of cancer diagnoses among children who are younger than 15 years of age. ALL occurs in about one of every 29,000 children in the United States each year, and AML accounts for about 10,600 new cases of leukemia annually. Approximately 700 cases of AML occur in people under the age of 20 each year.
Understanding Blood Cells
Normally, the body produces bone marrow stem cells (immature cells) that develop into mature blood cells. The three types of mature blood cells are:
- Red blood cells that carry oxygen and other materials to all tissues of the body
- White blood cells that fight infection and disease
- Platelets that help prevent bleeding by causing blood clots to form.