- Risk Factors
- Signs & Symptoms
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.
Adult acute myeloid leukemia (AML) is a cancer of the blood and bone marrow. This type of cancer usually gets worse quickly if it is not treated. It is the most common type of acute leukemia in adults. AML is also called acute myelogenous leukemia, acute myeloblastic leukemia, acute granulocytic leukemia, and acute nonlymphocytic leukemia.
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
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.
This summary is about adult AML. See the following PDQ summaries for information about other types of leukemia:
- Childhood Acute Myeloid Leukemia/Other Myeloid Malignancies Treatment
- Chronic Myelogenous Leukemia Treatment
- Adult Acute Lymphoblastic Leukemia Treatment
- Childhood Acute Lymphoblastic Leukemia Treatment
- Chronic Lymphocytic Leukemia Treatment
- Hairy Cell Leukemia Treatment
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.
Smoking, previous chemotherapy treatment, and exposure to radiation may affect the risk of developing adult AML.
Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor. 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.
Possible signs of adult AML include fever, feeling tired, and easy bruising or bleeding.
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:
- 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.
Tests that examine the blood and bone marrow are used to detect (find) and diagnose adult AML.
The following tests and procedures may be used:
- Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.
count (CBC): A procedure in which a sample of blood is drawn and
checked for the following:
- The number of red blood cells, white blood cells, and platelets.
- The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
- The portion of the sample made up of red blood cells.
- Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.
- Peripheral blood smear: A procedure in which a sample of blood is checked for the presence of blast cells, number and kinds of white blood cells, the number of platelets, and changes in the shape of blood cells.
- Bone marrow aspiration and biopsy: The removal of bone marrow, blood, and a small piece of bone by inserting a hollow needle into the hipbone or breastbone. A pathologist views the bone marrow, blood, and bone under a microscope to look for signs of cancer.
- Cytogenetic analysis: A laboratory test in which the cells is a sample of blood or bone marrow are viewed under a microscope to look for certain changes in the chromosomes.
- Immunophenotyping: A process used to identify cells, based on the types of antigens or markers on the surface of the cell. This process is used to diagnose the subtype of AML by comparing the cancer cells to normal cells of the immune system.
- Reverse transcriptionâ€“polymerase chain reaction test (RTâ€“PCR): A laboratory test in which cells in a sample of tissue are studied using chemicals to look for certain changes in the structure or function of genes. This test is used to diagnose acute promyelocytic leukemia (APL).
Certain factors affect prognosis (chance of recovery) and treatment options.
The prognosis (chance of recovery) and treatment options depend on:
- The age of the patient.
- The subtype of AML.
- Whether the patient received chemotherapy in the past to treat a different cancer.
- Whether there is a history of a blood disorder such as myelodysplastic syndrome.
- Whether the cancer has spread to the central nervous system.
- Whether the cancer has been treated before or recurred (come back).
It is important that acute leukemia be treated right away.
Once adult acute myeloid leukemia (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. In adult acute myeloid leukemia (AML), the subtype of AML and whether the leukemia has spread outside the blood and bone marrow are used instead of the stage to plan treatment. The following tests and procedures may be used to determine if the leukemia has spread:
- Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
- Lumbar puncture: A procedure used to collect cerebrospinal fluid from the spinal column. This is done by placing a needle into the spinal column. This procedure is also called an LP or spinal tap.
- Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs in the abdomen and make echoes. The echoes form a picture of body tissues called a sonogram. The picture can be printed to be looked at later.
There are three ways that cancer spreads in the body.
When cancer cells spread outside the blood, a solid tumor may form. This process is called metastasis. The three ways that cancer cells spread in the body are:
- Through the blood. Cancer cells travel through the blood, invade solid tissues in the body, such as the brain or heart, and form a solid tumor.
- Through the lymph system. Cancer cells invade the lymph system, travel through the lymph vessels, and form a solid tumor in other parts of the body.
- Through solid tissue. Cancer cells that have formed a solid tumor spread to tissues in the surrounding area.
The new (metastatic) tumor is the same type of cancer as the primary cancer. For example, if leukemia cells spread to the brain, the cancer cells in the brain are actually leukemia cells. The disease is metastatic leukemia, not brain cancer.
There is no standard staging system for adult AML.
The disease is described as untreated, in remission, or recurrent.
Untreated adult AML
In untreated adult AML, the disease is newly diagnosed. It has not been treated except to relieve symptoms such as fever, bleeding, or pain, and the following are true:
- The complete blood count is abnormal.
- At least 20% of the cells in the bone marrow are blasts (leukemia cells).
- There are signs or symptoms of leukemia.
Adult AML in remission
In adult AML in remission, the disease has been treated and the following are true:
- The complete blood count is normal.
- Less than 5% of the cells in the bone marrow are blasts (leukemia cells).
- There are no signs or symptoms of leukemia in the brain and spinal cord or elsewhere in the body.
Recurrent Adult AML
Recurrent AML is cancer that has recurred (come back) after it has been treated. The AML may come back in the blood or bone marrow.