Endocrine Abstracts

Leukaemia is the most common childhood cancer with an excellent 5-year survival rate of >80%, but many survivors face long-term health consequences. Low risk patients who were treated with chemotherapy-only are at risk of obesity and the metabolic syndrome. Endocrine and cardiometabolic abnormalities are common in high risk patients who required adjunct cranial irradiation and/or haematopoietic stem cell transplantation (HSCT) with/without total body irradiation (TBI). Growth failure is reported in 20–80% of childhood HSCT survivors with mean 1-2 S.D. loss to genetic target height. Gonadal failure may present with pubertal problems/infertility, and severity is associated with the type and dosage of conditioning therapy. Females are more often affected than males and almost all who had fractionated TBI>12 years old will develop ovarian failure. Some males progress through puberty spontaneously with virilisation, but have small testes as Leydig cells are more radiation resistant than Sertoli cells. Thyroid disorders can present as subclinical/primary hypothyroidism, or autoimmune hypo/hyperthyroidism. TBI is associated with increased risk of thyroid malignancy, hence regular monitoring is essential and further investigations should be instigated if indicated. Cardiometabolic abnormalities such as diabetes mellitus, hypertension and dyslipidaemia are increasingly recognised in HSCT survivors without raised body mass index. Impaired glucose tolerance is reported in 26–33% and diabetes mellitus in 9.5–17%. The aetiology of diabetes is often a combination of reduced beta-cell reserve and insulin resistance, but can also be autoimmune. Fasting glucose and HbA1c are unreliable in identifying survivors with diabetes and oral glucose tolerance tests are recommended. The presentations of diabetes are variable and treatment must be individualised. There is conflicting reports on bone health in survivors of HSCT with likely greater reduction in bone mineral density with increasing age than general population. Further research into the rehabilitation of survivors is required to reduce long term morbidity and early mortality.