Bone Abstracts

Objectives: Endocrine late effects, including osteopathologies, following diagnosis and treatment of childhood malignancies are studied in adult survivors with alarming results. However, in pediatric patients with brain tumors the risk to develop endocrine late effects is high even during childhood and adolescence.

Aim and design: To investigate osteopathologies and endocrine function in juvenile survivors of pediatric brain tumors we conducted a cross-sectional analysis in the hematology and oncology outpatient clinic at the University Children’s Hospital Essen, Essen, Germany. The study was approved by the local ethics committee (DRKS: 00003636). After informed consent was obtained, a thorough clinical and biochemical assessment of endocrine function (hypothalamic-pituitary-gonadal/thyroidal/adrenal axes) and signs of osteopathologies, (biochemical, radiographic and anamnestic parameters) was performed in 102 patients (42 female).

Results: 50% of the patients displayed impaired function of at least one of the investigated endocrine axis. 20% of the patients experienced fractures after chemotherapy, but only 3 patients reported frequent fractures. 12% of patients reported bone pain after physical activity. 25 OH-vitamin D₃ levels <20 ng/ml were observed in 77% of the patients. 38% presented with 25 OH-vitamin D₃ levels <10 ng/ml and 11% with secondary hyperparathyroidism. Using an expert rating, 28% of patients were diagnosed with osteopathologies. Osteopathologies were more frequent in children with endocrine impairments (not significant). A positive association of cumulative vincristine dose, but not of methotrexate, and the presence of osteopathology was observed.

Discussion: Impaired endocrine function and bone health are present in about 50% of juvenile patients after treatment for childhood brain tumors. Our results point towards a possible dosage effect of vincristine for the development of osteopathologies, however we could not confirm previous observations of negative effects of methotrexate on bone health.

Conclusion: Impaired bone health is a frequent finding in young survivors of brain tumors. Identification of children at risk is difficult and requires continuous assessment of clinical, biochemical and radiological measures. Adequate supplementation of vitamin D is recommended to avoid secondary hyperparathyroidism.

Conflict of interest: None.

Disclosure: The authors declared no competing interests.