The impact of adjuvant radiotherapy on overall survival in spinal low-grade gliomas: a propensity score-matched analysis.

Abstract

Introduction: Spinal low-grade gliomas (sLGGs) are a group of tumors that arise from glial cells in the spinal cord. Current evidence supporting the use of adjuvant radiotherapy for the management of sLGG is lacking. We hence aimed to compare overall survival rates in patients receiving surgery alone with those receiving surgery with adjuvant radiotherapy.

Methods: The NCDB, a large, nationwide, US-based cancer registry was used. Relevant cases were identified using the following ICD-O-3 histological codes: 9382, 9384, 9400, 9410, 9411, 9420, 9421, 9424, 9425, and 9450, along with the ICD-O-3 topographical codes for spinal meninges (C70.1) and spinal cord (C72.0), excluding spinal ependymomas. Overall survival was the primary outcome. Propensity score matching 1:1 was used to balance the cohorts prior to Kaplan-Meier survival analysis.

Results: A total of 552 patients were included in the study, with 440 in the surgery alone group and 156 in the surgery with adjuvant radiotherapy group. Patients in the surgery with adjuvant radiotherapy group were significantly older (median age 40.0 vs. 24.0 years, p < 0.001), and exhibited higher proportions of WHO grade 2 tumors (p < 0.001). Adjuvant chemotherapy was more frequently administered in the surgery with adjuvant radiotherapy group (23% vs. 7%, p < 0.001). Overall, adjuvant radiotherapy was not associated with improved survival, with a significantly higher mortality in the radiotherapy group before propensity score matching (p < 0.0001). After matching, the difference in overall survival was no longer significant (p = 0.11).

Conclusion: This study found no significant overall survival benefit associated with the use of adjuvant radiotherapy for spinal low-grade gliomas (sLGG). Although patients who received adjuvant radiotherapy initially demonstrated higher mortality rates, this difference was largely due to confounding factors such as more advanced disease in this group.