Which demographic group is most commonly affected by chronic myeloid leukemia?

Chronic myeloid leukemia (CML) is primarily a disease that affects older adults, with the majority of cases diagnosed in individuals over the age of 50. This demographic is particularly susceptible due to the accumulation of genetic mutations over time that contribute to the development of this type of leukemia. The median age at diagnosis for CML is typically around 65 years old, which further underscores the trend of higher incidence in older adults.

In contrast, children and adolescents tend to be less affected by CML, as it is exceedingly rare in these age groups. Childhood leukemias are more often of the acute type rather than chronic. Young adults in their 20s represent another demographic that does not show a significant incidence of CML; the disease generally manifests later in life. The pathophysiology of CML involves the Philadelphia chromosome resulting from a translocation between chromosomes 9 and 22, which is associated with age-related factors.

Given this information, it is clear that the age group most commonly affected by chronic myeloid leukemia is adults over 50 years old.