Pretreatment Endocrine Disorders Due to Optic Pathway Gliomas in Pediatric Neurofibromatosis Type 1: Multicenter Study

Context: Up to 20% of children with neurofibromatosis type 1 (NF1) develop low-grade optic pathway gliomas (OPGs) that can result in endocrine dysfunction. Data on prevalence and type of endocrine disorders in NF1-related OPGs are scarce. Objectives: The aim of the study was to determine the prevalence of endocrine dysfunctions in patients with NF1 and OPGs and to investigate predictive factors before oncological treatment. Design: Multicenter retrospective study. Settings and patients: Records were reviewed for 116 children (64 females, 52 males) with NF1 and OPGs followed at 4 Italian centers. Main outcome measures: We evaluated endocrine function and reviewed brain imaging at the time of OPG diagnosis before radio- and chemotherapy and/or surgery. OPGs were classified according to the modified Dodge classification. Results: Thirty-two children (27.6%) with a median age of 7.8 years had endocrine dysfunctions including central precocious puberty in 23 (71.9%), growth hormone deficiency in 3 (9.4%), diencephalic syndrome in 4 (12.5%), and growth hormone hypersecretion in 2 (6.2%). In a multivariate cox regression analysis, hypothalamic involvement was the only independent predictor of endocrine dysfunctions (hazard ratio 5.02 [1.802-13.983]; P = .002). Conclusions: Endocrine disorders were found in approximately one-third of patients with Neurofibromatosis type 1 and OPGs before any oncological treatment, central precocious puberty being the most prevalent. Sign of diencephalic syndrome and growth hormone hypersecretion, although rare, could be predictive of optic pathway gliomas in NF1. Tumor location was the most important predictor of endocrine disorders, particularly hypothalamic involvement.