Leukemia Risk Factors

Woman smoking a cigarette.

Certain factors can make 1 person more likely to get leukemia than another person. These are called risk factors. Although such risk factors do exist, a person who has 1 or more risk factors will not necessarily get leukemia. In fact, a person can have many risk factors and still not get leukemia, or he or she can have no known risk factors and still get the disease.

Some risk factors, such as having a rare congenital disease, are out of a person's control. Other risk factors, such as smoking, are lifestyle choices a person can control. The following are known risk factors for leukemia:

  • Smoking. People who smoke are more likely to get AML than people who do not smoke.

  • Chemical exposure. Being exposed for a long period of time to certain chemicals, such as benzene, is a known risk factor. Chemicals used in the rubber and shoe industries may also increase a person's risk of developing leukemia.

  • Radiation exposure. High doses of radiation, such as those from an atomic bomb blast or a nuclear reactor accident, increase a person's risk of getting AML and ALL. Radiation therapy to treat other cancers may also increase the risk of leukemia. 

  • Chemotherapy drugs. People who receive certain chemotherapy drugs to treat other cancers are more likely to get AML or ALL. In these cases, a person's risk of leukemia is higher for a number of years after the first cancer is treated. But this small increased risk of getting leukemia later on does not outweigh the need to use these drugs in treating the cancer.

  • Rare congenital diseases. A very small number of people are at greater risk for acute leukemia because they have certain rare diseases from the time they are born. For example, people with Down syndrome, ataxia telangiectasia, and Bloom syndrome also have an increased risk of developing acute forms of leukemia.

  • Certain blood disorders. People who have certain blood diseases, such as myelodysplastic syndromes, are more likely to develop leukemia. 

  • Family history. Most people who get leukemia do not have a family history of it. But people with relatives who have CLL may be at increased risk.