Endocrine Late Effects of Targeted and Immune-Based Therapies in Pediatric Oncology

Advances in pediatric oncology have markedly improved survival, shifting attention toward long-term treatment-related morbidity. Targeted agents and immune-based therapies are now widely used across pediatric malignancies and selected non-malignant conditions, often for prolonged periods and during critical windows of growth and development. Because many therapeutic targets regulate physiological pathways involved in growth, pubertal maturation, gonadal function, bone metabolism, and energy homeostasis, clinically relevant endocrine toxicity may emerge during treatment or become apparent only with extended follow-up. This narrative review summarizes pediatric evidence on endocrine and metabolic effects associated with major classes of targeted and immune-based therapies, including tyrosine kinase inhibitors, mTOR inhibitors, MAPK-pathway inhibitors (BRAF/MEK), TRK inhibitors, ALK inhibitors, immune checkpoint inhibitors, and immune effector therapies. Distinct patterns of endocrine vulnerability emerge across drug classes: growth impairment and bone-mineral alterations are most consistently reported with tyrosine kinase inhibitors; weight gain and metabolic changes predominate with MAPK-, TRK-, and ALK-targeted agents; immune checkpoint inhibitors are characterized by early, multi-axis immune-related endocrinopathies with a high likelihood of permanent hormone deficiency once established. In contrast, endocrine abnormalities observed after immune effector therapies largely reflect indirect effects of systemic inflammation, corticosteroid exposure, and prior hematopoietic stem cell transplantation rather than direct endocrine toxicity. Given the limited pediatric-specific data, frequent confounding by multimodal therapy, and the potential for delayed or irreversible endocrine sequelae, structured endocrine monitoring and long-term survivorship care are essential for children exposed to modern anticancer therapies.