Prepubertal Initiation of Imatinib is Associated with Reduced Final Height in Children with Chronic Myeloid Leukemia

Area of Science:

• Pediatric Oncology
• Hematology
• Endocrinology

Background:

• Imatinib is a tyrosine kinase inhibitor used to treat chronic myeloid leukemia (CML).
• Growth deceleration has been observed in children receiving imatinib, but long-term effects on final height are less understood.

Purpose of the Study:

• To evaluate the impact of prolonged imatinib therapy on linear growth in children with CML who have reached skeletal maturity.
• To determine if the timing of imatinib initiation relative to pubertal development influences final height.

Main Methods:

• A cross-sectional study included 13 patients with CML diagnosed before age 13 and who had attained skeletal maturity.
• Data collected included anthropometry, sexual maturity, bone age, and longitudinal height from medical records.
• Height z-scores at diagnosis and skeletal maturity were compared with population-specific growth charts.

Main Results:

• Mean height z-score decreased from -0.6 at diagnosis to -1.1 at skeletal maturity (p=0.04).
• Patients initiating imatinib before the pubertal growth spurt showed a significant decline in height z-score (-0.5 to -1.3, p=0.03).
• No significant height z-score decline was observed in those starting imatinib after the pubertal growth spurt (p=0.60).

Conclusions:

• Prolonged imatinib therapy in children with CML leads to reduced final height, particularly when initiated before puberty.
• Despite some catch-up growth during adolescence, final height z-scores remain reduced at skeletal maturity.
• This study provides long-term follow-up data on the effects of imatinib on growth in pediatric CML patients.