Acute myeloid leukemia (AML) is a form of leukemia, or cancer of the body’s blood-forming cells. It is the most common form of acute leukemia in adults. Also known as acute myelogenous leukemia, AML affects the body’s blood making system, including:

• Bone marrow. Bone marrow is the soft, inner component of bones. All forms of blood cells are produced in the bone marrow including:
  
  
• • White blood cells (cells that fight infection).
    
    
  • Red blood cells (cells that carry oxygen to tissues all over the body).
    
    
  • Platelets (cells that help develop blood clots and control bleeding).
    
    
• Lymphatic system. A network of glands, organs and ducts responsible for filtering and extracting fluid from tissues, as well as producing and storing the cells needed by the body to fight infections and diseases.

In patients with AML, the bone marrow usually manufactures a large number of abnormal white blood cells. In rarer cases of AML, abnormal red blood cells or platelet-producing cells are produced. With time, these cells can begin to build up, leaving less room for normal white blood cells, red blood cells and platelets. As a result, the immune system becomes weakened and the body is unable to fight infections and blood clotting is impaired. Reduced amounts of red blood cells is called anemia and decreased platelets is referred to as thrombocytopenia.

AML develops in the bone marrow, but the leukemic cells typically spread quickly into the blood. Eventually, they can spread farther into the lymph nodes, liver, spleen, brain, spinal cord and testicles. With successful treatment, remissions are frequent and some patients are cured.

The exact cause of AML has not been identified. However, researchers have gained a greater understanding of how specific changes in DNA can cause cells to develop into leukemia. A number of risk factors have also been identified, including smoking and exposure to very high levels of radiation. 

Symptoms of AML vary depending on where it has spread in the body. General signs and symptoms include weight loss, fever, loss of appetite, fatigue and weakness. Infections, pallor, bleeding or easy bruising are also common signs.

AML may be first detected in routine blood tests. However, additional tests, including bone marrow tests, are typically needed to verify the diagnosis. The treatment and prognosis for AML depends on the subtype of the disease, as well as certain additional factors including the patient’s age. It may include chemotherapy, radiation therapy, and bone marrow/stem cell transplantation. AML patients often receive a combination of these therapies for treatment of the disease.

The American Cancer Society (ACS) predicts that in 2007 there will be about 13,500 new cases of AML in the United States. The disease is more common in older adults, with the average age being 65 years. The prognosis is worse for older patients, with a five-year survival rate for people over age 65 at about 4 percent. The overall AML survival rate in adults under age 65 is approximately 33 percent. However, other factors, including the patient’s general health, can affect the prognosis.