A risk factor is something that affects a person's chance ofgetting 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 are rarely absolute. 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 had any known risk factors.

There are very few known risk factors for CML and for most cases, no cause is found.

High-dose radiation exposure

Being exposed to high-dose radiation (such as being a survivor of an atomic bomb blast or nuclear reactor accident) is the only known environmental risk factor for chronic myeloid leukemia.

Age and gender

The risk of getting CML increases with age. This disease is slightly more common in males than females, but it's not known why.

There are no other proven risk factors for CML. The risk of getting CML does not seem to be affected by smoking, diet, exposure to chemicals, or infections. And CML does not run in families.

Last Medical Review: 11/05/2009
Last Revised: 11/05/2009