Spinal location is prognostic of survival for solitary-fibrous tumor/hemangiopericytoma of the central nervous system

BackgroundPrior studies have highlighted infratentorial tumor location as a prognostic factor for solitary fibrous tumor (SFT) and hemangiopericytoma (HPC) of the central nervous system (CNS), and spinal location is considered a positive prognostic factor for other tumors of the CNS. While SFT/HPC of the CNS is known to frequently arise from the spinal meninges, there are no case series that report outcomes for spinally located CNS tumors, and their prognosis in relation to intracranial and other CNS-located tumors is unknown.ObjectiveTo investigate outcomes for patients with SFT/HPC of the spinal meninges.MethodsThe Surveillance, Epidemiology, and End-Results Program was used to identify patients with SFT/HPC within the CNS from 1993-2015. We retrospectively analyzed the relationship between tumor location (spinal vs. Brain and other CNS) and survival.ResultsWe identified 551 cases of CNS SFT/HPC, 64 (11.6%) of which were primary tumors of the spinal meninges. Spinal tumors were more likely than brain and other CNS tumors to be SFT vs. HPC (37.5 vs. 12%, p<0.001), benign (42.2 vs. 20.3%, p<0.001), and less than 5cm (53.1 vs. 35.7%, p<0.001). The 10-year survival rates for spinal and brain/other CNS tumors were 85 and 58%, respectively. Median survival time was significantly longer for spinal tumors (median survival not reached vs. 138months, p=0.03, HR=0.41 [95% CI 0.18-0.94]). On multivariable analysis, spinal tumor location was associated with improved survival over tumors located in the brain and other CNS (HR=0.36 [95% CI 0.15-0.89], p=0.03).ConclusionSpinal tumor location is associated with improved survival in patients with SFT/HPC of the CNS. Larger institutional studies are necessary to characterize the relationship between tumor location and other relevant factors such as presentation and amenability to gross-total resection and adjuvant radiotherapy. Future studies exploring optimal management of spinally located tumors are also needed.