ESPE Abstracts

Introduction: Growth hormone excess (GHE) in children with neurofibromatosis type 1 (NF-1) has been reported in some sporadic cases. Whether GHE stimulates progressive optic pathway glioma (OPG) growth is of concern. The prevalence of GHE in NF-1 has not been described and the scheme treatment has not been well characterized.

Objective: To describe in children with NF-1/OPG and GH excess the treatment regimen and long term response to long- acting octeotride.

Population and methodology: Descriptive study including NF-1-OPG patients with GHE followed in a terciary hospital between 2008–2018. The diagnosis of GHE was established from acceleration of growth, high levels of insulin-like growth factor 1 (IGF-1 >1DS) and the absence of GH suppression (glucose tolerance test). Clinical and laboratory data, secondary side effects and the response to treatment were also described.

Results: From our cohort, 80/ 379 children with NF-1 were diagnosed of OPG (21%). In a prospective follow up 7/80 patients were identified as having GHE; all were prepubertal, 5 boys (71%), mean age of 4.4±1.9 years. The mean height at the moment of diagnosis of GHE was +0.87±1.38 SD (> 0.86±0.76 SD above the midparental height); growth velocity increased from +0.35±1.19 SD to +4.07±2.7, mean IGF-1 > 1SD (457.8±151.3 ng/mL). In 4 patients the GHE was observed during progression of OPG (3) or neurocutaneous fibroma (1). The first three patients were initially treated with short-acting octreotide in a daily subcutaneously dose (1.5 μg/kg/day). After confirming efficacy and tolerability, it was replaced by long-acting preparation of octeotride (Sandostatin-LAR 10 mg/28 days, intramuscular). Four patients were initially treated with (10 mg/28 d), one needed to increase the dose to 20 mg. After 3 months, 6/7 patients showed a normalization of IGF-1 and growth velocity. Treatment was stopped in 4 patients after 21.85±0.72 months, and they remained stable for 26.6 months (12-49 months). Three patients are still on treatment (15.9±6.9 months). Except for mild diarrhea, no other adverse events were observed.

Conclusions: We should consider the risk of GH excess in patients with NF-1- OPG, and this may be a cause for concern. Treatment with long -acting octeotride was effective and safe. After treatment, auxological and analytical parameters remained within normal range, confirming GH excess reversibility.