Classification and Treatment of Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy and accounts for 25% of cancers that occur before 15 years of age and 19% among persons less than 20 years of age (Ries et al. 1999). Based on the most recent estimates from the Surveillance, Epidemiology and End Results (SEER) Program of the National Cancer Institute (NCI), there are about 3,000 cases of ALL diagnosed in the United States each year among persons less than 20 years of age. The incidence peaks at 80–90 cases/million at 2–3 years of age, begins to drop abruptly at age 5–6 years reaching a rate of about 20 cases/million at 8–11 years of age, and then gradually decreases to an annual rate of about 10 cases/million by 20 years of age.