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Chronic myelogenous leukemia

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Risk factors for chronic myelogenous leukemia

A risk factor is something (such as a behaviour, substance or condition) that increases the risk of developing cancer. Most cancers are the result of many risk factors, but sometimes chronic myelogenous leukemia (CML) develops in people who don’t have any of the risk factors described below.

The risk of developing CML increases with age. It usually occurs in people over the age of 65 years. Men develop CML more often than women.

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.

You may wonder about benzene. There is significant evidence showing that there is no association between benzene and CML.

Known risk factors

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

High doses of radiation

Exposure to high doses of radiation is a risk factor for CML. Survivors of the atomic bomb explosions in Japan during the Second World War have a higher risk of developing CML. People exposed to radiation from nuclear reactor accidents also have a higher risk of developing CML.

Exposure to formaldehyde

Studies have shown that exposure to formaldehyde increases the risk of myelogenous leukemias. Factory workers, chemical workers, embalmers and other people may be exposed to formaldehyde in the workplace. Embalmers tend to have longer-term exposure and higher overall exposure to formaldehyde than industry workers. People with higher exposure to formaldehyde (both exposure level or length of exposure) have an increased risk of developing CML.

Possible risk factors

The following factors have been linked with CML, but there is not enough evidence to show they are known risk factors. Further study is needed to clarify the role of these factors for CML cancer.

Previous radiation therapy

Radiation therapy given to treat cancer or other health conditions increases the risk of secondary leukemia. The leukemia is more commonly acute myelogenous leukemia (AML). But radiation may also increase the risk for CML.

Being overweight or obese

People who are overweight or obese have a higher risk of developing certain types of cancer. Some studies have shown that people who are overweight have a higher risk of developing leukemia than people with a normal body weight.

Unknown risk factors

It isn’t known whether or not the following factors are linked with CML. It may be that researchers can’t show a definite link or that studies have had different results. Further study is needed to see if the following are risk factors for CML:

  • smoking
  • farming, agricultural and related exposures
  • previous chemotherapy

Questions to ask your healthcare team

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


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