Childhood acute lymphoblastic leukemia

Even though childhood acute lymphoblastic leukemia (ALL) is the most common type of cancer in children, it is still considered a rare disease. In the Unites States, a disease is defined as rare when it affects fewer than 200,000 people at a given time.

There are approximately 2,900 children and adolescents younger than 20 years of age diagnosed with ALL each year in the United States. Over the past 25 years, there has been a gradual increase in the incidence of ALL. The incidence is highest among children age 2 to 3 years. It appears to be highest in Hispanic children, and is substantially higher in white children than in black children.

The long-term outlook (prognosis) for people with childhood acute lymphoblastic leukemia (ALL), including the potential for long-term cure, depends on the severity of the condition, laboratory features, and treatment. Factors that may affect prognosis include the age and white blood cell count at the time of diagnosis; biologic characteristics of the leukemia cells; response to chemotherapy; and the amount of cancer cells that remain during treatment or remission. This information can be used to assess the risk for each affected person.

Overall, the cure rate for childhood ALL is more than 80%. Five-year survival rates for children rose to 90% from 2000-2005. Improvement in survival has been seen for all age groups of children, except for infants younger than 1 year (who have a poor outcome). In low-income countries, treatment results have been less encouraging.

Potential acute complications can include tumor lysis syndrome, renal failure, sepsis, bleeding, thrombosis (development of a blood clot), inflammation of the cecum (typhlitis), neuropathy, encephalopathy, or seizures.

Lifelong follow-up is necessary because survivors may have late complications from the treatment, such as secondary malignancy, short stature, growth hormone deficiency, learning disabilities, or cognitive defects.