The impact of cancer therapy on the endocrine system in survivors of childhood brain tumours

Abstract

Survival rates are improving following cancer therapy for childhood brain tumours. There is therefore a growing cohort of survivors at risk of late effects of cancer therapy. Endocrine problems are very common in these patients. The recognition and prompt management of these are essential to prevent further morbidity and impairment of quality of life.Cranial radiation can damage hypothalamic-pituitary function, most frequently affecting GH status; however, higher radiation doses may cause more widespread hypothalamic-pituitary damage. Early puberty secondary to cranial irradiation is now being managed with gonadotrophin-releasing hormone analogues to improve final height. Prompt diagnosis and management of GH deficiency may improve final height outcome; continued GH therapy beyond final height aids the achievement of adult body composition (lean body mass and bone mass) and GH therapy in adulthood improves quality of life. Both cranial irradiation alone and with spinal irradiation can result in radiation damage to the thyroid resulting in hypothyroidism and thyroid nodules, a high proportion of which are malignant. Gonadal damage secondary to spinal irradiation and adjuvant chemotherapy may have long-term consequences including infertility.

Hypogonadism After Childhood Cancer Treatment

“…All patients with secondary hypogonadism had hiposomatotropism as well, which corresponds to reports of others (Constine et al 1993, Gleeson & Shalet 2004). …”

Revealing the large-scale network organization of growth hormone-secreting cells

“…Therefore, our 3D approach to functional analysis of the GH network could have importance in human pituitary pathophysiology. One can imagine that the development of noninvasive imaging of the present 3D network [e.g., with selective ligands for GH cells for positron-emission tomography (PET) scans] (33) might be useful in diagnosis of some gradually developing GH-deficiency states, such as those after traumatic brain injury (34,35) or cranial irradiation (36). GH cell network disruption could well contribute to the uncoordinated GH profiles seen in GHD subjects otherwise described as exhibiting ''neurosecretory dysfunction.…”

Disorders of ovarian function in childhood and adolescence: evolving needs of the growing child. An endocrine perspective

“…10 CXRT also has major global effects on learning, short-term memory and memory processing. When a recipient of childhood CXRT is seen as a young adult, it is important to recognise memory impairment.…”