What is Acute Myeloid Leukemia (AML)?
Acute myeloid leukemia (AML) is a cancer that affects the blood and bone marrow. It is also called acute myelogenous leukemia, acute myeloblastic leukemia, acute myelocytic leukemia, acute granulocytic leukemia, and acute non-lymphocytic leukemia.
AML develops from myeloid cells. These are cells that normally develop into red blood cells, platelets, and white blood cells. “Acute” means that AML grows fast and can progress quickly, making prompt treatment important.1,2
The cells that make up the blood, including white blood cells, red blood cells, and platelets, are made in the bone marrow. When a myeloid cell becomes cancerous, it rapidly multiplies and crowds out normal, healthy cells. AML begins in the bone marrow and can quickly spread to other areas such as the central nervous system and lymph nodes.1,2
What causes AML?
The exact causes of AML are unknown, but it begins with damage to the DNA of the cell. That damage may be inherited (genetic) or acquired (develop as a result of exposure to something in the environment). Most cases of AML are thought to result from acquired mutations that occur over time.1
How does AML develop?
Blood is made up of several different cells, each with its own purpose. Red blood cells carry oxygen to the tissues. Platelets help stop bleeding by creating clots. White blood cells are the immune system’s primary defense and fight infections. Each of these blood cells are created in the bone marrow, the spongy center of bones.
The bone marrow contains blood stem cells, which are immature cells that can turn into different types of cells. The stem cells change into myeloid cells or lymphoid cells. Myeloid cells can become white blood cells, red blood cells, and platelets.3,4 AML is a blood cancer that develops from myeloid cells, includes into many subtypes.1,2
What are the different types of AML?
There are many different subtypes of AML, and the subtype helps guide treatment recommendations. The subtypes are categorized by the cell type. Some of the AML subtypes include:
- Acute promyelocytic leukemia
- Acute myelomonocytic leukemia
- Acute monocytic leukemia
- Acute erythroid leukemia
- Acute megakaryoblastic leukemia
- Acute basophilic leukemia2
Who gets AML?
AML is more common in older adults, although it can rarely occur in younger adults or children. The average age of diagnosis for AML is 68. AML is slightly more common in men than women. It is a relatively rare cancer, accounting for about 1 percent of all cancers. An estimated 21,450 new cases will be diagnosed in 2019.5
What factors increase a person's risk of developing AML?
Risk factors are characteristics that can increase someone's chances of developing a disease like AML. Some of the known risk factors for AML include:
- Long-term exposure to high levels of benzene, a chemical found in gasoline, the rubber industry, the chemical industry, cigarette smoke, and some cleaning products
- Previous treatment with certain chemotherapy drugs, like alkylating and platinum agents or topoisomerase II inhibitors
- Exposure to high-dose radiation, like being a survivor of an atomic bomb or nuclear reactor accident
- Certain other blood cancers, including chronic myeloproliferative neoplasms or myelodysplastic syndrome
- Some genetic syndromes, including Fanconi anemia, Bloom syndrome, Ataxia-telangiectasia, Diamond-Blackfan anemia, Schwachman-Diamond syndrome, Li-Fraumeni syndrome, neurofibromatosis type 1, and severe congenital neutropenia
- Some chromosomal syndromes, like Down syndrome or trisomy8
- Family history of AML
- Being male
- Getting older1,2
What are the common symptoms of AML?
People with AML may experience symptoms due to the crowding out of healthy blood cells, such as:
- Anemia, a lack of red blood cells that can cause paleness and fatigue
- Low platelet count, which can result in bleeding or bruising
- Low white blood cell count, which can cause frequent infections or mild fever1,2
Other common symptoms of AML include:
- Weight loss
- Loss of appetite
- Night sweats
- Pain or discomfort in the bones or joints
- Enlarged spleen or liver
- Swollen gums1,2
How is AML staged?
A standard staging system does not exist for AML.4 AML is generally classified by its subtype, which can help to guide treatment decisions.1,4
What is the prognosis for AML?
The prognosis for AML differs by subtype, but in general, people over 60 years old tend to have worse outcomes than younger patients. AML can be a hard disease to treat, but the survival rate for all leukemias, including AML, has improved in recent years.
Based on data from 2009-2015, the National Cancer Institute found the 5-year survival rate for AML overall is 28.3 percent.5 The 5-year survival rate for children and adolescents (younger than 15 years) with AML ranges from 65 to 75 percent.6
Cancer survival rates are created using earlier outcomes of people who survive a set amount of time after diagnosis. In cancer estimates, the “5-year survival rate” is a common marker. It is important to remember that many people live more than 5 years after diagnosis. These statistics may not be accurate for every person with AML.