Chronic lymphocytic leukemia epidemiology and demographics

Epidemiology
CLL is a disease of the elderly and is rarely encountered in individuals under the age of 40. Thereafter the disease incidence increases with age. Of note, subclinical "disease" can be identified in up to 7-8% of individuals over the age of 70. That is, small clones of B cells with the characteristic CLL phenotype can be identified in many healthy elderly persons. The clinical significance of these cells is unknown.