What are risk factors?

Doctors do not understand the exact cause of leukaemia (sometimes spelt leukemia). But there are certain things that may increase your risk of developing it.

Below we talk about the risk factors for the four main types of leukaemia.

Causes of acute myeloid leukaemia (AML)

The cause of acute myeloid leukaemia (AML) is not known. But research is going on all the time to find out more about it. Like other cancers, AML is not infectious and cannot be passed on to other people.

There are some things that may increase your risk of developing AML. Having one or more risk factors does not mean you will get AML. People with no known risk factors can still develop it.

Age

AML is more common in people aged 60 and over.

Radiation

Exposure to very high radiation levels increases the risk of developing AML. For example, there might be high levels of radiation after a nuclear accident. Very few people in the UK will be exposed to radiation levels high enough to increase their risk.

Radon is a naturally occurring radioactive gas. Research has shown that a person’s risk of developing AML is not significantly increased by exposure to radon gas.

Exposure to chemicals

Rarely, AML is diagnosed in people who have been exposed to certain chemicals over many years. This includes people who have worked in jobs using benzene and other solvents.

Smoking

Smoking increases the risk of developing AML. Researchers think this may be because there is benzene in cigarette smoke.

Chemotherapy and radiotherapy

Rarely, people who have had certain types of chemotherapy or radiotherapy develop AML a few years later. This is called secondary leukaemia or treatment-related AML.

Blood disorders

People with certain blood disorders, such as myelodysplasia or myeloproliferative disorders, have a higher risk of developing AML.

Genetic conditions

People with certain genetic conditions have a higher risk of developing leukaemia. This includes Down’s syndrome and Fanconi’s anaemia.

Family history

Sometimes AML or another blood cancer affects several relatives in a family. If you are worried about leukaemia in your family, talk to your GP or specialist doctor.

Causes of acute lymphoblastic leukaemia (ALL)

The cause of acute lymphoblastic leukaemia (ALL) is not known. But research is going on all the time to find out more about it. Like other cancers, ALL is not infectious and cannot be passed on to other people.

People with certain genetic conditions have a higher risk of developing leukaemia. This includes Down’s syndrome and Fanconi’s anaemia.

It is possible that some people are born with a gene change that makes them more likely to develop ALL. More research is needed to understand this.

Causes of chronic lymphocytic leukaemia (CLL)

We do not know what causes chronic lymphocytic leukaemia (CLL), but research is going on to find out more about it. Certain things called risk factors can increase the risk of developing it.

Age

The risk of developing CLL increases with age. Most people diagnosed with CLL are over 60. It is rare in people under 40.

Sex

CLL is more common in men than women.

Family history

Most people with CLL have no family history of it. But studies show that there is an increased risk of developing CLL if you have a close relative (parent, sibling or child) who has it. If anyone else in your family has CLL, it is important to let your specialist know. But most people who have a relative with CLL will never develop it themselves.

CLL is not infectious and cannot be passed on to other people.

Ethnicity

CLL is most common in people of European origin.

Causes of chronic myeloid leukaemia (CML)

It is not clear why people get chronic myeloid leukaemia (CML). It is not linked to smoking, diet or exposure to chemicals. Like other cancers, CML is not infectious and it cannot be passed on to other people. And it does not run in families. There are some factors that might increase the risk of developing CML.

Age

CML can happen at any age. But it is more common as people get older. Over half of the people diagnosed with CML in the UK are over 65.

Gender

CML is slightly more common in men than women.

Radiation exposure

Exposure to very high radiation levels increases the risk of developing CML. For example, these might be the high levels of radiation following a nuclear accident. Very few people in the UK will be exposed to radiation levels high enough to increase their risk.

Research has found no link between the risk of developing CML and:

  • living near nuclear power stations
  • exposure to electro-magnetic fields
  • living near high-voltage electricity cables
  • household radon (naturally occurring gas).

About our information


  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editors, Dr Anne Parker, Consultant Haematologist; and Dr Helen Marr, Consultant Haematologist.

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