ESPE Abstracts

Background and Aims: Optic pathway gliomas (OPGs) represent 2-5% of brain tumors in children. OPGs are classified by the anatomic location and whether they are associated with neurofibromatosis type 1 (NF1). Children with OPGs face sequelae related to tumor location and treatment modalities, including visual dysfunction, neurologic deficits, and endocrine dysfunction. The aim of our study was to assess the prevalence of endocrine dysfunctions in patients with OPGs and to compare the outcomes between those with and without NF1.

Methods: This retrospective single center study included patients diagnosed with OPGs between 1990 and 2020, younger than 18 years at diagnosis, followed at our endocrine clinic. Data about demographic parameters, presence/absence of NF1, OPGs treatment related data, growth and puberty parameters and occurrence of endocrine dysfunction were retrieved from their medical records. Variables were compared between groups (OPGs with and without NF1).

Results: Of the 59 patients (29 males) fulfilling the study criteria, 36 (61%) had NF1, with higher rates of isolated optic nerve involvement (P < 0.01). Patients without NF1 compared to those with NF1 were significantly younger at diagnosis of OPGs (1.5 vs. 4.2 years, P = 0.04), older at the last visit (14.7+ 6.3 vs. 11.5 ± 5.0, P = 0.03), and a higher percentage of them were treated with surgery (65% vs. 8%, P < 0.01), chemotherapy (83% vs. 31%, P < 0.01) or cranial radiation (14% vs. 3%, P = 0.13). At the last visit, patients without NF1 compared to those with NF1 had lower height SDS (-0.97±1.39 vs. -0.72±1.13, P = 0.45), and higher BMI SDS (1.08±1.26 vs. 0.37+1.02, P = 0.02). No significant difference was found between the groups in the age at pubertal onset. Patients without NF1 had higher rates of endocrine complications (65% vs. 28%, P < 0.001), including: central hypothyroidism (48% vs. 2.8%, P < 0.01), hypogonadotropic hypogonadism (22% vs. 2.8%, P = 0.02), diabetes insipidus (26% vs. 2.8%, P = 0.01) and hyperlipidemia (35% vs. 8.3%, P = 0.01), without significant differences in the rate of growth hormone deficiency or precocious puberty. Median age at the time of diagnosis of the first endocrinopathy was younger in patients without NF1 compared to those with NF1, 3.75 years (1.18-10.87) vs. 8.25 years (6.72-8.62), respectively, P = 0.341. In a multivariate regression analysis, surgery was the independent predictor of endocrine dysfunctions (OR 13.3 [2.23-79.53]; P < 0.01).

Conclusions: Patients with OPGs without NF1 had a higher rate of endocrine dysfunction presenting at a younger age compared to patients with NF1, which may be associated with tumor location and more aggressive treatments.