Overview

Leukemia is a cancer of the blood. Leukemia begins when normal blood cells change and grow uncontrollably. Acute myeloid leukemia (AML) is a cancer affecting white blood cells. AML may sometimes be called acute myelogenous leukemia, acute myelocytic leukemia, or acute nonlymphocytic leukemia. Unlike chronic leukemia, acute leukemia develops quickly and generally requires immediate treatment. AML occurs in people of all ages but is most common in adults older than 65.

AML is a disorder of the process that normally produces neutrophils, a type of white blood cell. Neutrophils fight infections caused by bacteria. The production of mature neutrophils usually is highly regulated. For example, the body rapidly makes more neutrophils during an infection and returns to a regular level of production when the infection is controlled. Mature neutrophils develop from immature white cells in a process called differentiation.

In AML, acquired mutations (damage to the genetic material or DNA) in the blood-forming cells disrupt the normal process of differentiation, resulting in the increase of large numbers of immature (undeveloped) cells called myeloblasts or blasts. Blasts cannot function like fully developed, healthy blood cells. The large number of blasts also reduces the production of healthy red blood cells and platelets. Therefore, people with AML are usually anemic (because they do not have enough red blood cells), susceptible to infection (because they do not have enough mature neutrophils), and bruise or bleed easily (because of a low level of platelets).

AML is usually found in the blood and bone marrow (the spongy, red tissue in the inner part of the large bones), but it can sometimes also invade other sites, such as the brain, skin, and gums. Occasionally, AML cells can form a solid tumor called a myeloid sarcoma or chloroma that may be located nearly anywhere in the body.

This section is about AML in adults. Read about childhood AML.

Statistics

In 2009, an estimated 12,810 people of all ages (6,920 males and 5,890 females) in the United States will be diagnosed with AML. AML is the second most common type of leukemia diagnosed in adults. An estimated 9,000 deaths (5,170 males and 3,830 females) will occur in 2009.

The five-year relative survival rate (percentage of people who survive at least five years after the cancer is detected, excluding those who die from other diseases) of people with AML is 22%. However, it is important to note that survival depends on several factors, including biologic features of the disease and patient age (see Subtypes for more information). Although AML is a serious disease, it is treatable with chemotherapy.

Cancer survival statistics should be interpreted with caution. These estimates are based on data from thousands of cases of this type of cancer in the United States each year, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with AML. Because the survival statistics are measured in five-year intervals, they may not represent advances made in the treatment or diagnosis of this cancer.

Statistics adapted from the American Cancer Society's publication, Cancer Facts and Figures 2009.

Find out more about basic cancer terms used in this section.