Risk Factors for Chronic Myeloid Leukemia (CML)

There are very few known risk factors for chronic myeloid leukemia (CML).

A risk factor is anything that raises your chances of getting a disease like cancer. Different cancers have different risk factors. Some risk factors, like smoking, can be changed. Others, like your age or family history, can’t be changed.

But having a risk factor, or even many risk factors, doesn’t mean that you will get the disease. And some people who get the disease may have few or no known risk factors.

Here is what we know about the risk factors for CML.

Getting older

While CML can happen at any age, the risk goes up as you get older.

• The average age of people when they are diagnosed with CML is around 66 years.
• About 7 out of 10 people with CML are 55 or older.

Being male

CML is slightly more common in males than in females. The reason for this is not clear.

Radiation exposure

Exposure to high-dose radiation (such as being a survivor of an atomic bomb blast or nuclear reactor accident) increases the risk of getting CML. Radiation treatment for cancer and certain other diseases has also been linked to an increased risk of CML.

The possible increased risk of leukemia from lower levels of radiation (such as from imaging tests like x-rays or CT scans) isn’t well understood. Being exposed to this type of radiation, especially very early in life, might increase the risk of leukemia. But it isn’t clear how much of a risk this poses.

If there is an increased risk, it’s likely small. But to be safe, most doctors try to limit radiation exposure from tests as much as possible, especially in children and pregnant women.

To learn more, see X-rays, Gamma Rays, and Cancer Risk.

Other risk factors

There are no other clear risk factors for CML. The risk of getting CML doesn’t seem to be affected by smoking, diet, exposure to chemicals, or infections. Having a family history of CML isn’t linked with an increased risk.