Background and Objectives:
CML is a myeloproliferative neoplasm characterized by the dysregulated production and uncontrolled proliferation of mature and maturing granulocytes with fairly normal differentiation. It mainly affects adults, and is rarely seen in children. The average age at diagnosis of CML is around 64 years. There are few studies describing CML in adolescents and young adults. In Qatar we have one of the largest cohorts of adolescents and young adults with CML. This study aims to study this cohort and find out if there are any differences from older patients with CML.
Methods:
A retrospective analysis of 169 patients with CML treated at NCCCR over a 23-year period, 83 of them are younger than 40 years at diagnosis (adolescents and young adults) vs. 86 age 40 or older at diagnosis (controls). Comparison was done of all characteristics at diagnosis, including: gender, BMI, ethnicity, CBC parameters, spleen size, Sokal score, bone marrow findings, treatment modality, with response assessment using ELN guidelines.
Results:
Both groups were matched with regards to gender and ethnicity. Adolescents and young adults had higher WBC count and larger spleen on diagnosis compared to controls (174.1 vs. 142.2; and 18.0 vs. 15.6). 4 young patients presented in blast-phase vs. 1 in control group. 5 adolescents and young adults underwent allogeneic stem cell transplant vs. 1 patient in the control group. During a mean follow up of 70.7 months in adolescents and young adults vs. 72.7 months in the control group there were 2 deaths vs. 1 respectively. However, there were no other significant differences between the two groups, with regards to TKI used, or response at 1 year / latest assessment.
Conclusions:
Based on this data we may conclude that CML present more aggressively in adolescents and young adults as compared with older patients, however there is no difference in outcome. This might reflect different underlying etiology / better tolerance to treatment in the younger group.
No relevant conflicts of interest to declare.
Author notes
Asterisk with author names denotes non-ASH members.