Risk Factors for Chronic Myelomonocytic Leukemia (CMML)

A risk factor is anything that increases your chance of getting a disease, such as cancer. Different cancers have different risk factors. For example, exposing skin to strong sunlight is a risk factor for skin cancer. Smoking is a risk factor for lung cancer and many other cancers.

But people with few or no known risk factors can still get a disease. And having a risk factor, or even several, does not mean that you will get that disease.

Because chronic myelomonocytic leukemia (CMML) is rare, it has been hard to study. For a long time, it was grouped with myelodysplastic syndromes. As a result, we only know of a few risk factors for CMML.

Older age

The risk of CMML increases with age. This disease is rare in people younger than 40. Most cases of CMML are found in people 65 and older.

Being male

CMML is about twice as common in men as in women. The reason for this is not clear.

Prior cancer treatment

Prior treatment of cancer with chemotherapy and radiation seems to increase the risk of CMML. However, the risk of CMML after cancer treatment is not as high as the risk of other blood problems, such as myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML).

See Second Cancers in Adults for more on this.