Endocrine late effects of childhood cancers

Long-term survival in children with cancer has increased markedly in the past 15 years. However, impaired linear growth and thyroid dysfunction that vary according to the age at diagnosis and treatment and to the dose and duration of radiation and chemotherapy have been described in these patients. The impact of cranial irradiation on the hypothalamic-pituitary-adrenal axis and on pubertal maturation has been less well studied. A positive correlation between the age at diagnosis and the age at onset of puberty in children who have been treated with high-dose cranial radiation therapy for central nervous system (CNS) tumors has been found recently. Frank adrenal insufficiency is uncommon after high-dose CNS irradiation, but alterations in the hypothalamic-pituitary-adrenal axis do occur. Assessments of the effects of newer modes of radiation therapy such as hyperfractionated craniospinal radiation suggest a lower incidence of primary hypothyroidism in the long term.