What are the risk factors for acute myeloid leukemia?
A risk factor is something that affects your chance of getting a disease, such as cancer. For example, exposing skin to strong sunlight is a risk factor for skin cancer. Smoking is a risk factor for a number of cancers.
But risk factors don’t tell us everything. Having a risk factor, or even several risk factors, does not mean that you definitely will get the disease. And many people who get the disease may not have had any known risk factors. Even if a person has a risk factor and develops cancer, it is often very hard to know how much that risk factor may have contributed to the cancer.
There are a few known risk factors for acute myeloid leukemia (AML).
The only proven lifestyle-related risk factor for AML is smoking. Many people know that smoking is linked to cancers of the lungs, mouth, throat, and larynx (voice box), but few realize that it can also affect cells that don’t come into direct contact with smoke. Cancer-causing substances in tobacco smoke are absorbed by the lungs and spread through the bloodstream to many parts of the body.
Certain chemical exposures
The risk of AML may be increased by exposure to certain chemicals. Long-term exposure to high levels of benzene is a risk factor for AML. Benzene is a solvent used in the rubber industry, oil refineries, chemical plants, shoe manufacturing, and gasoline-related industries, and is also present in cigarette smoke, and some glues, cleaning products, detergents, art supplies, and paint strippers.
Some studies have linked heavy workplace formaldehyde exposure to AML risk, but this link was not seen in other studies.
Patients who are treated with certain cancer chemotherapy (chemo) drugs are more likely to develop AML. Drugs called alkylating agents and platinum agents are linked to an increased risk of AML that peaks about 8 years after chemo. Often a patient will get a disease called myelodysplastic syndrome before the AML. Examples of alkylating agents include cyclophosphamide, mechlorethamine, procarbazine, chlorambucil, melphalan, busulfan, and carmustine. Platinum drugs include cisplatin and carboplatin.
Chemo drugs known as topoisomerase II poisons are also linked to AML. AML linked to these drugs tends to occur only a few years after treatment and without myelodysplastic syndrome developing first. Examples of topoisomerase II poisons include the drugs etoposide and teniposide, mitoxantrone, and the anthracyclines (epirubicin, doxorubicin).
For more information, see our document Second Cancers After Cancer Treatment.
High-dose radiation exposure (such as being a survivor of an atomic bomb blast or nuclear reactor accident) increases the risk of developing AML. Japanese atomic bomb survivors had a greatly increased risk of developing acute leukemia, usually within 6 to 8 years after exposure.
Radiation treatment for cancer has also been linked to an increased risk of AML. The risk varies based on the amount of radiation given and what area is treated, but is not as high as was seen after the atomic bomb blasts.
The possible risks of leukemia from exposure to lower levels of radiation, such as from x-rays or CT scans, are not well-defined. If a fetus is exposed to radiation within the first months of development, it may carry an increased risk of leukemia, but the extent of the risk is not clear. If there is an increased risk it is likely to be small, but to be safe, most doctors try to limit a person’s exposure to radiation as much as possible.
For more information, see our document X-rays, Gamma Rays and Cancer Risk.
Certain blood disorders
Patients with certain blood disorders seem to be at increased risk for getting AML. These include chronic myeloproliferative disorders such as polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis. The risk of developing AML is increased further if treatment for these disorders includes some types of chemotherapy or radiation.
Some patients who have myelodysplastic syndrome (MDS) may develop AML. Patients with MDS have low blood cell counts and abnormal cells in the blood and bone marrow. MDS can evolve over time into AML. Patients who develop AML after having MDS typically have a poor prognosis.
Some syndromes that are caused by genetic mutations (abnormal changes) present at birth seem to raise the risk of AML. These include:
- Fanconi anemia
- Bloom syndrome
- Blackfan-Diamond syndrome
- Schwachman syndrome
- Li-Fraumeni syndrome
- Neurofibromatosis I
- Severe congenital neutropenia (also called Kostmann syndrome)
Chromosome problems present at birth are also linked to a higher risk of AML, these include:
- Down syndrome (being born with an extra copy of chromosome 21)
- Trisomy 8 (being born with an extra copy of chromosome 8).
Although most cases of AML are not thought to have a strong genetic link, having a close relative (such as a parent or sibling) with AML increases your risk of getting the disease.
Someone who has an identical twin who got AML before they were a year old has a very strong risk of also getting AML.
AML is more common in males than in females, but the reasons for this are not clear.
Uncertain, unproven or controversial risk factors
Other factors that have been studied for a possible link to AML include:
- Exposure to electromagnetic fields (such as living near power lines)
- Workplace exposure to diesel, gasoline, and certain other chemicals and solvents
- Exposure to herbicides or pesticides
So far, none of these factors has been linked conclusively to AML. Research in these areas is ongoing.
Last Medical Review: 07/24/2013
Last Revised: 09/20/2013