Very long-term outcomes of pediatric patients treated for optic pathway gliomas: A longitudinal cohort study

Abstract Background Optic pathway gliomas (OPG) represent 5% of childhood brain tumors. Successive relapses lead to multiple treatments exposing to late complications. Methods We included patients treated at Gustave Roussy (GR) between 01.1980 and 12.2015 for OPG, before 18 years-old and alive at 5 years from diagnosis. Mortality and physical health conditions data were extracted from medical data files and updated thanks to the GR long-term follow-up program and French national mortality registry for patients included in the French Childhood Cancer Survivor Study. Results We included 182 5y-OPG-childhood survivors in the analysis (sex-ratio M/F 0.8, 35% with NF1). With a median follow-up of 17.2y (range=5-41), we registered 82 relapses, 9 second malignancies and 15 deaths as first events after 5 years, resulting in 20-y conditional overall survival (C-OS) and late events-free survival (LEFS) of 79.9% (95%CI=71-86) and 43.5% (95%CI=36-51) respectively. NF1 (Hazard ratio HR=3, 95%CI=1.4-6.8), hypothalamic involvement (HR=3.2, 95%CI=1.4-7.3), and radiotherapy (HR=2.8, 95%CI=1.1-6.7) were significantly associated with C-OS in multivariable analyses. Ninety-five percent of 5y-OPG survivors suffered from any health condition, especially visual acuity “<1/10” (n=109), pituitary deficiency (n=106) and neurocognitive impairment (n=89). NF1 (HR 2.1) was associated with precocious puberty. With a median time post diagnosis of 4.2 years, 33 cerebrovascular events were observed in 21 patients. Conclusion Late relapses, second malignancies and cerebrovascular diseases are severe late events resulting in premature mortality. Morbidity is high and needing after-cancer care to improve quality of life. Risk factors could be considered to better stratify long-term follow-up.