Characteristics and risk factors for CLL

Adult patients with the following features have a higher chance of developing CLL:

  • Age: The risk of developing CLL increases with age. Only about 10% of CLL patients are younger than 55 years.
  • Gender: Men are about twice as likely as women to develop CLL.
  • Ethnicity: CLL is more commonly seen in White people than in any other ethnic group.
  • Family history: Family members of CLL patients have a 6-9% increased risk for getting CLL.
  • Monoclonal B-cell lymphocytosis (MBL): Approximately 1-2% of MBL patients will develop CLL each year.

MBL is defined as having fewer than 5×109/L genetically identical B‑cells in the blood, and the exclusion of any other disorders in which B-cells are produced in excessive quantities. Unlike CLL, MBL does not require treatment.