Risk factors for leukemia

A risk factor is something that increases the risk of developing cancer. It could be a behaviour, substance or condition. Most cancers are the result of many risk factors. But sometimes leukemia develops in people who don’t have any of the risk factors described below.

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

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.

Risk factors are generally listed in order from most to least important. But in most cases, it is impossible to rank them with absolute certainty.

Risk factors


Radiation therapy and chemotherapy




Family cancer syndromes

There is convincing evidence that the following factors increase your risk for leukemia.

High levels of radiation

Coming into contact with high levels of radiation – for example, radiation from nuclear reactor accidents – is a risk factor for leukemia.

Previous radiation therapy and chemotherapy

Radiation therapy given in the past to treat cancer or other health conditions increases the risk of leukemia. Chemotherapy given in the past to treat cancer also increases the risk. Having had both radiation therapy and chemotherapy to treat cancer increases the risk more than having had the individual treatments alone.


Smoking tobacco increases the risk of some types of leukemia, and it may increase the risk for other types.

Breathing in benzene

Benzene is found in unleaded gasoline and is used by the chemical industry. People may breathe in benzene at work or in the general environment or by using certain products. Benzene increases the risk of leukemia.

Breathing in formaldehyde

Some studies have shown that breathing in formaldehyde increases the risk of leukemia. Factory workers, chemical workers, embalmers and other people may come into contact with formaldehyde at work. Embalmers are at a higher risk of leukemia because they tend to have contact for a longer time and use more formaldehyde in their work.

Family cancer syndromes

Some conditions are linked to an increased risk of cancer, including leukemia, because of an inherited gene mutation (a change in the gene). These conditions are called family cancer syndromes or inherited (hereditary) cancer syndromes. Most family cancer syndromes are rare. Family cancer syndromes can lead to leukemia in both children and adults.

  • Down syndrome
  • Fanconi anemia
  • ataxia-telangiectasia
  • Bloom syndrome

Possible risk factors

Overweight and obesity are possible risk factors for leukemia. This means that they have been linked with leukemia, but there is not enough evidence to show for sure that they are risk factors.

Questions to ask your healthcare team

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

Expert review and references

  • Checkoway H, Dell LD, Boffetta P, Gallagher AE, Crawford L, Lees PS, Mundt KA . Formaldehyde exposure and mortality risks from acute myeloid leukemia and other lymphohematopoietic malignancies in the US National Cancer Institute cohort study of workers in formaldehyde industries.. Journal of Occupational and Environmental Medicine. 2015: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4479664/.
  • Gentry PR, Rodricks JV, Turnbull D, Bachand A, Van Landingham C, Shipp AM, Albertini RJ, Irons R. . Formaldehyde exposure and leukemia: critical review and reevaluation of the results from a study that is the focus for evidence of biological plausibility. Critical Reviews in Toxicology. 2013.
  • International Agency for Research on Cancer (IARC). Volume 100D: Radiation: A Review of Human Carcinogens. 2011: http://monographs.iarc.fr/ENG/Monographs/vol100D/mono100D.pdf.
  • International Agency for Research on Cancer (IARC). Volume 100E: Personal Habits and Indoor Combustions. 2012: http://monographs.iarc.fr/ENG/Monographs/vol100E/mono100E.pdf.
  • International Agency for Research on Cancer (IARC). Volume 100F: Chemical Agents and Related Occupations: A Review of Human Carcinogens. 2012: http://monographs.iarc.fr/ENG/Monographs/vol100F/index.php.
  • International Agency for Research on Cancer (IARC). Volume 100B: Biological agents: a review of human carcinogens. 2012: http://monographs.iarc.fr/ENG/Monographs/vol100B/mono100B.pdf.
  • International Agency for Research on Cancer (IARC). Volume 112: Some Organophosphate Insecticides and Herbicides: Diazinon, Glyphosate, Malathion, Parathion, and Tetrachlorvinphos. 2015: http://monographs.iarc.fr/ENG/Monographs/vol112/index.php.
  • Linet, M.S., Devesa, S.S., & Morgan, G.J. . The leukemias. Schottenfeld, D. & Fraumeni, J. F. Jr. (eds.). Cancer Epidemiology and Prevention. 3rd ed. New York: Oxford University Press; 2006: 44: pp. 841-871.
  • National Toxicology Program . 14th Report on Carcinogens . Department of Health and Human Services ; 2016 .
  • Saberi Hosnijeh F, Romieu I, Gallo V, Riboli E, Tjonneland A, Halkjaer J, et al . Anthropometric characteristics and risk of lymphoid and myeloid leukemia in the European Prospective Investigation into Cancer and Nutrition (EPIC). Cancer Causes and Control. 2013.

Reducing your risk for leukemia

There are no specific ways to reduce the risk of leukemia. It is important for anyone who has symptoms to see their doctor as soon as possible.

Medical disclaimer

The information that the Canadian Cancer Society provides does not replace your relationship with your doctor. The information is for your general use, so be sure to talk to a qualified healthcare professional before making medical decisions or if you have questions about your health.

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