Risk
Factors

What are the risk factors for CLL?

There are a few risk factors that may affect a person’s chance of chronic lymphocytic leukemia (CLL). People with many risk factors may never develop CLL, while others with no risk factors can still get the disease. The cause of CLL is unknown. A few risk factors associated with CLL include:

• Age: CLL is more common in older adults with 90% of people diagnosed being over 50. The average age at diagnosis is 71.
• Race/Ethnicity: B cell CLL is more common in people of Russian and European descent, and is rare in people of Chinese, Japanese or Southeast Asian descent. It also occurs commonly in black people.
• Family History: Having more than 1 close relative with CLL or another lymph-related cancer may be linked with an increased risk of CLL; although this is uncommon. People with a first-degree relative with CLL (e.g. parent, sibling, child) are 2-4 times more likely to develop CLL.
• Gender: CLL is more common in men than women.
• Exposure to Radiation or Chemicals: There is no evidence that exposure to radiation, chemicals, or chemotherapy increases a person’s risk of CLL; however some studies have associated exposure to Agent Orange, a chemical used during the Vietnam War, to an increased risk of CLL.

Additional Resources: Information on Risk Factors
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