The role of radiotherapy and chemotherapy in adult optic nerve gliomas: a SEER-based analysis

Abstract Background: Optic nerve gliomas (ONGs) are uncommon tumors of the central nervous system in adults. The aim of this study was to define their characteristics, prognostic factors, and the impacts of adjuvant radiotherapy (RT) and chemotherapy on outcomes. Methods: Adult patients (age ≥18 years) with ONGs from the Surveillance, Epidemiology, and End Results (SEER) database were included. Univariate and multivariate Cox regression models were utilized to analyze the factors associated with survival. Kaplan-Meier method was used to evaluate the impacts of adjuvant therapies on overall survival (OS). Results: A total of 179 adult patients diagnosed with ONGs were identified between 1991 and 2016, with a median follow-up period of 64.0 months. The median age at diagnosis was 41.0 years. After excluding 18 patients with unknown information, the remaining patients included 142 (88.2%) low-grade tumors and 19 (11.8%) high-grade tumors. Multivariate analysis showed age at diagnosis, tumor grade, adjuvant chemotherapy were significant factors for OS. The 5-year OS rates for patients with low- and high-grade ONGs were 85.5% and 10.5%, respectively. The employment of adjuvant RT or chemotherapy would significantly shorten OS time in the low-grade group and could not prolong OS time in the high-grade group. Conclusions: This is the largest retrospective study of adult ONGs up to date. The overall prognosis of high-grade ONGs in adult patients is still poor despite multi-modality treatments. Adjuvant RT or chemotherapy might not be considered in adult patients with low-grade ONGs unless the malignant transformation or aggressive progression has been confirmed.