Endocrine Abstracts

Introduction: Several publications now demonstrate that growth hormone therapy in replacement doses does not increase the future risk of recurrence in brain tumours. However, there is less certainty about the best and safest time to start growth hormone (GH) therapy after completion of primary treatment with recent guidance suggesting that a delay of 1 year is appropriate. We plan to determine if the timing of GH initiation is related to the likelihood of tumour progression.

Method: We retrospectively reviewed data of 50 children currently on GH replacement therapy as a result of brain tumours after completion of primary treatment at a large tertiary paediatric endocrinology centre.

Results: 22 patients were male. The median age was 12.4 years (IQR 10.6 to 14.6) at last follow-up and median age at tumour diagnosis was 5.1 years (IQR 1.1 to 8.05). The most common diagnoses were craniopharyngioma (24%), low grade glioma (20%), medulloblastoma (14%), and germinoma (10%). One patient had a tumour predisposition syndrome (MEN1). 78% had primary surgical treatment, 62% received chemotherapy and 58% radiotherapy. Other endocrine deficits included TSH (32%), ACTH (18%) and LH/FSH (10%) deficiencies, posterior pituitary dysfunction (15%), and central precocious puberty (7%). The median time from end of treatment for diagnosis of GH was 0.83 years (IQR 0.04 to 3.04) with a height SDS at diagnosis of -1.22 (IQR -1.93 to -0.38). Median time of GH initiation after end of treatment (EOT) was 1.65 years (range 0.02 to 11.0). Only 9 progressed after starting GH, with a median time of GH initiation after EOT of 0.79 years (range 0.15 to 9.3) vs 1.73 years (range 0.02 to 11.0) in those who did not progress (P=0.96).

Conclusions: This analysis demonstrates no significant association of the timing of GH therapy in relation to the EOT and tumour progression. GH replacement can therefore be started as early as possible (even <1 year from EOT) in patients with brain tumours regardless of histology to maximise adult height and improve long-term bone density.