Leukemia

Leukemia is a cancer of the bone marrow and blood. The two primary types of leukemia are lymphocytic leukemia, which involves an increase of white blood cells called lymphocytes; and myelogenous leukemia (also known as myeloid or myelocytic leukemia), which involves an increase in white blood cells called granulocytes. Leukemia can be acute or chronic. Acute forms of leukemia progress rapidly, whereas chronic forms of leukemia progress slowly, leading to different approaches to diagnosis and treatment.

Risk Factors

Scientists do not fully understand all the causes of leukemia, but research has uncovered many associations. For example, chronic exposure to benzene in the workplace and exposure to large doses of radiation have been shown to cause leukemia in some cases.¹ Additionally, cancer-causing chemicals in tobacco may be associated with myeloid leukemia in adults.² Family history has also been associated with increased risk of leukemia.³ Caucasians are more likely than African Americans to develop acute leukemia,⁴ but scientists do not know why.

Statistics

In 2008 (the most recent year numbers are available)—

• 37,605 people in the United States were diagnosed with leukemia, including 21,503 males and 16,102 females.*†
• 22,431 people in the United States died from leukemia, including 12,758 males and 9,673 females.*†

For more information, visit Cancer Among Children.

*Incidence and death counts cover approximately 100% of the U.S. population.

†Source: U.S. Cancer Statistics Working Group. United States Cancer Statistics: 1999–2008 Incidence and Mortality Web-based Report. Atlanta (GA): Department of Health and Human Services, Centers for Disease Control and Prevention, and National Cancer Institute; 2012. Available at: http://www.cdc.gov/uscs. (full site)