Spinal Metastasis from Supratentorial Glioblastoma: A Registry-Based Case Series and a Review of the Literature

Background: Spinal metastasis is a rare complication of supratentorial glioblastoma. We report the clinical features and prognosis of this phenomenon and review the relevant literature. Methods: This is a territory-wide, multicentre, retrospective review using data from the Hong Kong High-grade Glioma Registry from 2006 to 2023. Data of consecutive adult patients diagnosed with supratentorial glioblastoma and spinal metastasis were extracted and analyzed. Results: Among the 1342 patients with supratentorial glioblastoma, 15 were diagnosed to have spinal metastasis (1.1%). The median time to spinal metastasis from the initial diagnosis of glioblastoma was 38.7 weeks (IQR: 15.1-57.6). Multi-level spinal involvement was present in 60% (9/15) of patients. Neither the topographical location of the tumor in relation to the subventricular zone, extent of resection, occurrence of intraoperative ventricular entry, nor methylguanine methyltransferase (MGMT) promoter methylation status predicted the time to spinal metastasis. The median overall survival was 44.1 weeks (IQR: 29.9-80.2), and the median post-spinal metastasis survival was 12.6 weeks (IQR: 5.0-15.0). Two-thirds of patients received spinal radiotherapy, 26.7% had systemic therapy (chemotherapy, targeted therapy, and/or immunotherapy), and 13.3% underwent surgical spinal decompression. No significant survival improvement was observed among patients who received spinal radiotherapy (HR: 0.61; 95% CI: 0.17-2.23) or systemic therapy (HR: 0.94; 95% CI: 0.20-4.39). Conclusions: This case series illustrates the management practices and clinical course of glioblastoma patients with spinal metastasis. No treatment modality was proven to be superior. Treatment remains largely palliative and should be tailored on an individual basis.