These factors place you at an increased risk of developing some types of leukemia :
- Cancer therapy. People who've had certain types of chemotherapy and radiation therapy for other cancers have a slightly greater risk of developing certain types of leukemia many years later.
- Genetics. Genetic abnormalities seem to play a role in the development of leukemia. Certain genetic diseases, such as Down syndrome, are associated with increased risk of leukemia.
- Exposure to radiation and certain chemicals. People exposed to very high levels of radiation, such as survivors of an atomic bomb blast or a nuclear reactor accident, have an increased risk of developing leukemia. Exposure to certain chemicals, such as benzene which is found in unleaded gasoline and tobacco smoke and used by the chemical industry also is linked to greater risk of some kinds of leukemia.
However, most people with known risk factors don't get leukemia. And many people with leukemia have none of these risk factors.
The above information thankfully comes from the Mayo Clinic.com at the following link.