Chronic Myeloid Leukemia in Adolescents and Young Adults: Clinicopathological Variables and Outcomes.

Introduction: Adolescents and young adults (AYAs) diagnosed with chronic myeloid leukemia (CML) constitute a significant demographic group, particularly in regions with youthful populations like Qatar. Despite the global median age of CML diagnosis being 65 years, Qatar's age distribution reflects a younger cohort. This study investigates whether AYAs with CML exhibit distinct clinicopathological characteristics or outcomes compared to older age groups.

Methods: A total of 224 CML patients were enrolled, including 114 AYAs (defined as ages 15 through 39). Demographic and clinical parameters, including gender, BMI, BCR-ABL1 transcript type, white blood cell (WBC) count, hemoglobin level, platelet count, and spleen size, were compared between AYAs and older patients. Prognostic scoring systems (Sokal, Hasford, EUTOS, and ELTS) and molecular response rates (MMR and DMR) were also evaluated.

Results: AYAs demonstrated higher WBC counts at diagnosis (median 142.3 vs. 120; p = 0.037) and lower hemoglobin levels (10.5 vs. 11.40; p = 0.004) compared to older patients. Spleen size was significantly larger in AYAs (18.8 vs. 15.5; p = 0.001). While AYAs showed better prognostic scores by Sokal and Hasford criteria, EUTOS and ELTS scores indicated comparable risk stratification. However, AYAs exhibited lower rates of MMR (56.7 vs. 73.4%; p = 0.016) and achieved MMR at a slower pace (median time 130 vs. 103 months; p = 0.064). Similarly, the percentage of DMR was lower in AYAs (37.1 vs. 46.8%; p = 0.175).

Conclusion: Despite their younger age, AYAs with CML displayed poorer prognoses compared to older patients. These findings underscore the importance of tailored management strategies for AYAs with CML to optimize outcomes in this distinct patient population.

Key point: AYAs are underrepresented in CML studies and risk scores, so this is the focus of this study.