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Types of Cancer > Leukemia > Leukemia-- Acute Myelogenous Leukemia (AML) > Overview
Acute Myeloid Leukemia (AML)
Carolyn Vachani, RN, MSN, AOCN
Affiliation:
The Abramson Cancer Center of the University of Pennsylvania
Last Modified: January 16, 2008
This article is a more specific discussion of AML. Please be sure to read Leukemia: The Basics first, so you have a basic understanding of leukemia.
What is AML?
AML is a blood cancer that affects white blood cells, red blood cells, and/or platelets. A person with AML develops abnormal numbers of these cells very quickly, giving the disease the name "acute". The white blood cell (WBC) count may be higher or lower than normal, but the WBCs that are being produced do not function well. Because WBCs are an important part of fighting infections, patients often have multiple infections that don't respond to treatment before they are diagnosed. Some people will have low red blood cell or platelet counts, but this is not always the case.
There will be an estimated 13,410 new cases diagnosed in 2007 in the United States, accounting for over 30% of all leukemia cases. AML can occur at any age, but is more common in adults, particularly over age 50, with the average age at diagnosis being 63 years. Also, it is also slightly more common in men than in women.
What causes AML?
Although we do not know what causes every case of AML, there are certain exposures that can increase risk. Exposure to ionizing radiation, such as from an atomic bomb or working in the nuclear industry, increases risk slightly (the increase has been seen in nuclear workers, but not people living near nuclear plants). Exposure to benzene increases the risk of developing AML. Smoking cigarettes is the most common way people are exposed to benzene, although some may be exposed to this chemical in their jobs. A history of blood or genetic disorders, such as myelodysplasia, Fanconi's Anemia, NF1 and Li Fraumeni syndrome all increase the risk of developing AML. Risk is also increased in children with Down's Syndrome (trisomy 21). There is an increased risk for people with a first-degree relative (parent, sibling, child) with the disease.
Previous treatment with chemotherapy or radiation can lead to AML, which is often called treatment-related AML and thought to account for between 10 and 20% of AML cases. The risk is thought to be most strongly associated with certain chemotherapy agents. Risk after radiation treatment alone, given without these chemotherapy agents, is relatively low. In the case of alkylating agents (ifosfamide, cisplatin, melphalan, cytoxan, etc.), AML most often occurs 5 to 7 years after exposure to the chemotherapy (known as a "latent period"), and tends to start as myelodysplastic syndrome, which is a bone marrow disorder that results in abnormal blood cell counts. AML caused by treatment with alkylating agents carries a poor prognosis, as the disease is often not responsive to treatment.
A second category of treatment-related AML are those cases caused by a group of medications called topoisomerase II inhibitors, which include etoposide, doxorubicin, daunorubicin and mitoxantrone. These cases generally occur less than 3 years after treatment with the agent. Unfortunately, they are also not very responsive to therapy and carry a poor prognosis.