What are the risk factors for acute myeloid leukemia?

A risk factor is something that increases a person's chance of getting a disease. Some risk factors, like smoking, can be controlled. Others, like a person's age, can't be changed. But risk factors don't tell us everything. Having a risk factor, or even several risk factors, does not mean that you will get the disease. And many people who get the disease may not have any known risk factors. Even if a person has a risk factor and gets cancer, it is often very hard to know how much that risk factor may have contributed to the cancer.

Risk factors for acute myeloid leukemia (AML)

There are a few known risk factors for AML.

Smoking

Smoking is a proven risk factor for AML. Many people know that smoking is linked to cancers of the lungs, mouth, and throat. But few know that it can also affect cells that do not come into direct contact with smoke. Cancer-causing substances in tobacco smoke get into the bloodstream and spread to many parts of the body.

Chemicals

Exposure to certain chemicals has been linked to acute leukemia. For instance, long-term exposure to high levels of benzene is a risk factor for AML. Benzene is a solvent used in cleaning. It is also used to produce drugs, plastics, dyes, gasoline, and other goods.

Patients with other cancers who are treated with certain chemotherapy drugs are more likely to develop AML. Using these drugs along with radiation treatment further increases the risk.

Radiation

Exposure to a high dose of radiation is a risk factor for AML. People who survived the atomic bomb in Japan had a greatly increased risk of getting acute leukemia, most within 6 to 8 years.

The risk of leukemia from lower levels of radiation, such as from radiation treatment, x-rays, or CT scans, is not clear. If a fetus is exposed to radiation within the first months of development, there might be an increase in the risk of leukemia. It is not clear how much the increase might be, but to be safe, most doctors try to limit a person's exposure to radiation as much as possible.

Certain blood problems

Patients with certain blood problems seem to be at a higher risk for getting AML. If your body makes too many red cells or not enough platelets, for instance, this may raise your risk. Some people with chronic myelogenous leukemia (CML -- another type of leukemia) later develop a form of AML. The risk of getting AML is higher if treatment for these other blood problems includes some types of chemotherapy or radiation.

Congenital (present at birth) syndromes

For the most part, AML does not appear to be an inherited disease. It is rare for it to run in families, so a person's risk is not usually increased if a family member has the disease. But there are some syndromes with genetic changes that seem to raise the risk of AML. These include:

• Down syndrome
• Fanconi anemia
• Bloom syndrome
• Ataxia-telangiectasia
• Blackfan-Diamond syndrome

Identical twin with AML

Having an identical twin with AML is a risk factor. This risk is mostly in the first year of life. Many doctors feel this increased risk may be due to leukemia cells being passed from one fetus to the other while still in the womb.

Gender

AML is more common in males than in females. The reasons for this are not clear.