Although the development of kinase inhibitors coincides with revolutionized clinical outcomes in pediatric patients with chronic myeloid leukemia (CML), age disparities in survival remain substantial, according to a study published in the European Journal of Cancer.1

The use of molecular therapies has improved therapeutic outcomes in adult patients with CML. Researchers therefore evaluated trends in survival and geographic disparities among children with CML prior to and after the introduction of kinase inhibitors in the United States and Southeastern Europe.

Investigators analyzed data from 369 patients aged 0 to 14 years with CML, as well as patients with acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML). Patients were included in 14 Southeastern European cancer registries and the Surveillance, Epidemiology, and End Results (SEER) database.

Among children with CML, 2-year survival ranged from 81% to 89% in the post-kinase inhibitor era compared with 49% to 66% in the pre-kinase inhibitor period, suggesting a 63% reduction in the risk of death with the introduction of targeted therapies (hazard ratio [HR], 0.37; 95% CI, 0.23-0.60).

Subgroup analyses showed that children aged than 5 years had a 3 times higher risk of death than those aged 10 to 14 years (HR, 3.03; 95% CI, 1.85-4.94), and patients living in Southeastern Europe had a 56% higher death risk than those treated in the United States (HR, 1.56; 95% CI, 1.01-2.42).

Age appeared to be a significant predictor of CML survival regardless of geographic area and period of kinase inhibitor administration. For example, among patients younger than 5 years, risk of death was 2.7 times higher than older children in the pre-kinase inhibitor period (HR, 2.71; 95% CI, 1.53-4.79) and 3.4 times higher in the era after the introduction of kinase inhibitors (HR, 3.38; 95% CI, 1.29-8.85).

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Although age disparities remain significant among pediatric patients with CML, the authors note that survival in the post-molecular therapy period now resembles survival in ALL.                      

Reference

  1. Karalexi MA, Baka M, Ryzhov A, et al. Survival trends in childhood chronic myeloid leukaemia in Southern-Eastern Europe and the United States of America. Eur J Cancer. 2016;67:183-190.