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Risk factors for leukemia

Any substance or condition that increases cancer risk is referred to as a risk factor. There isn’t a known, single cause of leukemia. Most cancers are the result of many risk factors. However, some people with leukemia do not have any identifiable risk factors.

Different types of leukemia have different risk factors. One risk factor may not increase the risk for all types of leukemia. Not all risk factors for the different types of leukemia are listed below.

Men are more likely than women to develop leukemia. The risk for developing most types of leukemia increases with age.

Risk factors

The following factors are known to increase the risk of developing some types of leukemia:

  • high doses of radiation (such as exposure to atomic bomb blasts or nuclear accidents)
  • radiation therapy given in the past to treat cancer or other health conditions
  • chemotherapy given in the past to treat cancer
  • radiation therapy combined with chemotherapy given in the past (the combination of treatments increases the risk more than the individual treatments)
  • exposure to benzene or formaldehyde
  • genetic syndromes (leukemia may develop in children with these syndromes)

Possible risk factors

Being overweight or obese is a possible risk factor for leukemia. This means that it has an association with leukemia, but there is not enough evidence to say that it is a known risk.

Unknown risk factors

The following are unknown factors for which there is not enough evidence or the evidence is inconclusive. In other words, it can’t be determined for sure whether these risks factors are or are not associated with leukemia:

  • farming, agricultural and related exposures (especially to herbicides or pesticides)
  • occupational exposure to certain chemicals or low-dose radiation
  • exposure to electromagnetic fields

To make the decisions that are right for you, ask your healthcare team questions about risks.

Down syndrome

A chromosome disorder that is associated with certain abnormal physical characteristics and varying degrees of mental retardation. It is caused by the presence of an extra chromosome 21.

Down syndrome is associated with an increased risk of developing some cancers, including leukemia.

Also called trisomy 21 syndrome.

Fanconi anemia

A rare genetic condition that affects the bone marrow so it cannot make red blood cells, white blood cells or platelets.

Fanconi anemia can turn into myelodysplastic syndrome (MDS) or leukemia.


A rare genetic disease that affects the nervous system, immune system and other body systems. Signs and symptoms include loss of balance, poor coordination, frequent infections, red eyes (due to widening of blood vessels) and abnormal eye movements.

Ataxia-telangiectasia is associated with an increased risk of developing some cancers, including leukemia and lymphoma.

electromagnetic field

An invisible area of electric and magnetic forces given off by power lines, electric appliances, radio waves and microwaves.

Also called electromagnetic radiation.


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