Acute myeloid
leukemia (AML) is a cancer of the blood and bone marrow. It usually progresses quickly if it is not treated. The disease accounts for about 10,600 new cases of leukemia each year, and it occurs in both adults and children.
Other names for AML include:
- Acute myelogenous leukemia
- Acute myeloblastic leukemia
- Acute granulocytic leukemia
- Acute non-lymphocytic leukemia.
Understanding AML and Blood Cells
Normally, the body produces bone marrow stem cells (immature cells) that develop into mature blood cells.
The three types of mature blood cells include:
- 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 stem cells usually develop into a type of white blood cell called myeloblasts (or myeloid blasts)
- The myeloblasts (or leukemia cells) are abnormal and do not mature into healthy white blood cells
- Leukemia cells are unable to do their usual work and can build up in the blood and bone marrow so there is less room for healthy white blood cells, red blood cells, and platelets.
This may lead to infection, anemia, or easy bleeding. 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.
There are different subtypes of AML that are based on:
- The type of blood cell that is affected
- How mature (developed) the cancer cells are at the time of diagnosis
- How different they are from normal cells.
The treatment for most subtypes of AML is similar. However, acute promyelocytic
leukemia is one subtype that is treated differently from the other types.
No one knows
what causes acute myeloid leukemia, and doctors can seldom explain why one person will get AML and another person will not. However,
leukemia research has shown that people with certain risk factors are more likely than others to develop it. A risk factor is anything that increases a person's chance of developing a disease.
- Having a brother or sister, especially a twin, with leukemia
- Being Hispanic
- Being exposed to cigarette smoke or alcohol before birth
- A history of myelodysplastic syndrome (pre-leukemia) or aplastic anemia
- Past treatment with chemotherapy or radiation therapy
- Exposure to ionizing radiation or chemicals, such as benzene
- Having certain genetic disorders, such as Down syndrome.
- Being male
- Smoking, especially after age 60
- Previous treatment with chemotherapy or radiation therapy
- Previous treatment for childhood acute lymphocytic leukemia (ALL)
- Exposure to atomic bomb radiation or the chemical benzene
- A history of a blood disorder, such as myelodysplastic syndrome.
Like all blood cells,
leukemia cells travel through the body. Depending on the number of abnormal cells and where these cells collect, patients with AML may have a number of symptoms.
- Fever, with or without an infection
- Shortness of breath
- Weakness or feeling tired
- Easy bruising or bleeding
- Petechiae (flat, pinpoint spots under the skin caused by bleeding)
- Pain in the bones or joints
- Pain or feeling of fullness below the ribs.
Other common childhood symptoms include painless blue or purple lumps in the neck, underarm, stomach, groin, or other parts of the body. These lumps are called
leukemia cutis. In some cases, painless lumps appear around the eyes. These lumps, called chloromas, may be blue-green.
The early signs of
adult AML may be similar to those caused by
the flu or other common diseases. Common symptoms in adults include:
- Fever
- Shortness of breath
- Easy bruising or bleeding
- Petechiae (flat, pinpoint spots under the skin caused by bleeding)
- Weakness or feeling tired
- Loss of appetite or unexplained weight loss.
These and other possible symptoms may be caused by leukemia or by other conditions. Therefore, people with possible symptoms of AML should see their doctor for proper diagnosis and treatment.
Tests that examine the blood and bone marrow are used to detect and diagnose AML
(see AML Diagnosis for more information about the specific tests used).
Once AML has been diagnosed, tests are done to find out if the cancer has spread to other parts of the body. The extent, or spread, of cancer is usually described as stages. However, in AML, there is no standard staging system. Instead, the disease is described as untreated, in remission, or recurrent. In AML, the subtype and whether the
leukemia has spread outside the blood and bone marrow are used to plan treatment.
Different types of treatment are available for AML. Some treatments are standard (the currently used treatment), and some treatments are being tested in clinical trials.
- Chemotherapy
- Radiation therapy
- Chemotherapy with stem cell transplant.
There are also two phases of treatment used for
childhood AML: induction therapy and consolidation/intensification therapy.
Current treatment options in adults include:
- Chemotherapy
- Radiation therapy
- Stem cell transplantation
- Other drug therapies.
There are also two phases of treatment for
adult AML: remission induction therapy and maintenance therapy.
Choosing the most appropriate treatment for AML is a decision that ideally involves the affected person, the family, and the healthcare team.
The prognosis and treatment options for AML will depend on:
- The person's age, general health, and number of white blood cells present at diagnosis
- Whether the AML was caused by previous anticancer treatment
- The subtype
- How well the leukemia responds to initial treatment
- Whether the AML is untreated or has recurred (come back) after being treated
- Whether there is a history of a blood disorder, such as myelodysplastic syndrome
- Whether the AML has spread to the central nervous system (brain and spinal cord) or to other parts of the body.
Important points to keep in mind about AML include the following:
- Acute myeloid leukemia (AML) is a type of cancer in which the bone marrow makes a large number of abnormal blood cells
- There are different subtypes of AML
- Tests that examine the blood and bone marrow are used to detect and diagnose AML
- Certain factors affect a person's prognosis and treatment options
- The American Cancer Society estimated that 11,960 people (6,530 men and 5,430 women) would be diagnosed with acute myeloid leukemia in 2005.
