Acute Lymphocytic Leukemia - Causes

Risk Factors

Acute lymphocytic leukemia is diagnosed in about 5, 300 Americans each year. Children account for two-thirds of these new cases.

Age

ALL in Children. ALL is the most common type of cancer diagnosed in children. ALL accounts for about 75% of cases of childhood leukemia. Each year, about 3,500 American children and adolescents are diagnosed with ALL. ALL can strike children of all ages, but is most likely to occur when children are 2 - 4 years of age. It is slightly more common in boys than in girls.

ALL in Adults. ALL is the least common type of leukemia among adults. About 1 in 3 cases of ALL occur in adults. Adults over age 50 have a higher risk for ALL than those between the ages of 20 - 50.

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Race and Ethnicity

Caucasian and Hispanic children have a higher risk for ALL than African-American children.

Hereditary Disorders

ALL does not appear to run in families. But certain inherited genetic disorders may increase risk. For example, children with Down syndrome have a 20-times greater risk of developing ALL than the general population. Other rare genetic disorders associated with increased risk include Klinefelter syndrome, Bloom syndrome, Fanconi anemia, ataxia-telangiectasia, neurofibromatosis, Shwachman syndrome, IgA deficiency, and congenital X-linked agammaglobulinemia.

Radiation and Chemical Exposure

Previous cancer treatment with high doses of radiation or chemotherapy can increase the risk for developing ALL. Prenatal exposure to x-rays may also increase risk in children. Lower levels of radiation (living near power lines, video screen emissions, small appliances, cell phones) are unlikely to pose any cancer risk.

Review Date: 01/27/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org).