A risk factor can be anything that influences the development of any cancer. But having a risk factor, or many does not give certainty of having particular cancer. Some people with no risk factors can also develop cancer.
The cause of CLL is not known. There is no evidence that exposure to chemotherapy, radiation, or chemicals increases the risk of a person developing CLL. However, these factors may also increase the risk of developing CLL –
- Family history. Although it is uncommon, having more than one close relative with CLL or other lymph-related cancer may be linked to an increased CLL risk. People with a first-degree relative with CLL, like a parent, sibling, or child, are 2 to 4 times more likely to develop CLL.
- Gender – Men are at higher risk of developing CLL than women.
- Age – CLL is most common in older adults, rare in young adults, and hardly develops in children. Approximately 90% of people diagnosed with CLL are older than 50 years. The average age for diagnosis of CLL is 71.
- Monoclonal B-cell lymphocytosis – This is a condition in which people have higher levels than usual lymphocytes. But, the levels are not high enough to classify as CLL. There is a slight risk that monoclonal B-cell lymphocytosis can turn into CLL.