Causes and risk factors
- The etiology of CLL is unknown, though research has shown that it is the only type that is not related to previous exposure to radiation, chemical agents, or chemotherapy.
- This disease is most commonly seen in people from Western countries, where it accounts for over 30% of all leukemias.
- People who have first-degree relatives with CLL have twice the risk of developing the disease as people who do not.
- CLL mainly affects men over age 60 and is rarely seen in people under 40.
- It appears that smoking does not increase the risk of developing the disease.