Adult Acute Myeloid Leukemia

Adult acute myeloid leukemia at a Glance

• Adult acute myeloid leukemia (AML) is the most common type of acute leukemia in adults.
• 60% to 70% of adults can attain complete remission following appropriate therapy.
• Risk factors include being male, smoking, chemotherapy or radiation therapy, childhood treatment for leukemia, benzene or high radiation exposure history of certain blood disorders.
• Symptoms include fever, shortness of breath, easy bruising or bleeding, petechiae, weakness or severe fatigue, weight loss or loss of appetite.

About AML

Adult acute myeloid leukemia (AML) is a type of cancer in which the bone marrow makes abnormal myeloblasts (a type of white blood cell), red blood cells, or platelets. This type of cancer usually gets worse quickly if it is not treated. It is the most common type of acute leukemia in adults.

Estimated new cases and deaths from acute myeloid leukemia (AML) in the United States in 2010 are 12,330 and 8,950 respectively. Approximately 60% to 70% of adults with AML can be expected to attain complete remission status following appropriate induction therapy. More than 25% of adults with AML (about 45% of those who attain complete remission) can be expected to survive 3 or more years and may be cured.

Normally, the bone marrow makes blood stem cells (immature cells) that develop into mature blood cells over time. A blood stem cell may become a myeloid stem cell or a lymphoid stem cell. The lymphoid stem cell develops into a white blood cell. The myeloid stem cell develops into one of three types of mature blood cells:

• Red blood cells that carry oxygen and other materials to all tissues of the body.
• White blood cells that fight infection and disease.
• Platelets that help prevent bleeding by causing blood clots to form.

In AML, the myeloid stem cells usually develop into a type of immature white blood cell called myeloblasts (or myeloid blasts). The myeloblasts in AML are abnormal and do not become healthy white blood cells. Sometimes in AML, too many stem cells develop into abnormal red blood cells or platelets. These abnormal white blood cells, red blood cells, or platelets are also called leukemia cells or blasts. Leukemia cells can build up in the bone marrow and blood so there is less room for healthy white blood cells, red blood cells, and platelets. When this happens, infection, anemia, or easy bleeding may occur. The leukemia cells can spread outside the blood to other parts of the body, including the central nervous system (brain and spinal cord), skin, and gums.

AML Subtypes

There are different subtypes of AML. Most AML subtypes are based on how mature (developed) the cancer cells are at the time of diagnosis and how different they are from normal cells.

Acute promyelocytic leukemia (APL) is a subtype of AML that occurs when parts of two genes stick together. APL usually occurs in middle-aged adults. Symptoms of APL may include both bleeding and forming blood clots.

Risk Factors

Anything that increases your risk of getting a disease is called a risk factor. Possible risk factors for AML include the following:

• Being male.
• Smoking, especially after age 60.
• Having had treatment with chemotherapy or radiation therapy in the past.
• Having had treatment for childhood acute lymphoblastic leukemia (ALL) in the past.
• Being exposed to atomic bomb radiation or the chemical benzene.
• Having a history of a blood disorder such as myelodysplastic syndrome.

Signs and symptoms

The early signs of AML may be like those caused by the flu or other common diseases. A doctor should be consulted if any of the following problems occur:

• Fever.
• Shortness of breath.
• Easy bruising or bleeding.
• Petechiae (flat, pinpoint spots under the skin caused by bleeding).
• Weakness or feeling tired.
• Weight loss or loss of appetite.