Invasiveness is associated with metastasis and decreased survival in hemangiopericytoma of the central nervous system

Abstract

Meningeal hemangiopericytoma (m-HPC) is a rare tumor of the central nervous system (CNS), which is distinguished clinically from meningioma by its tendency to recur and metastasize. The histological classification and grading scheme for m-HPC is still evolving and few studies have identified tumor features that are associated with metastasis. All patients at our institution with m-HPC were assessed for patient, tumor, and treatment characteristics associated with survival, recurrence, and metastasis. New findings were validated using the SEER database. Twenty-seven patients were identified in our institutional records with m-HPC with a median follow-up time of 85 months. Invasiveness was the strongest predictor of decreased overall survival (OS) and decreased metastasis-free survival (MFS) (p = 0.004 and 0.001). On subgroup analysis, bone invasion trended towards decreased OS (p = 0.056). Bone invasion and soft tissue invasion were significantly associated with decreased MFS (p = 0.001 and 0.012). An additional 315 patients with m-HPC were identified in the SEER database that had information on tumor invasion and 263 with information on distant metastasis. Invasion was significantly associated with decreased survival (HR = 5.769, p = 0.007) and metastasis (OR 134, p = 0.000) in the SEER data. In this study, the authors identified a previously unreported tumor characteristic, invasiveness, as the strongest factor associated with decreased survival and metastasis. The association of invasion with decreased survival and metastasis was confirmed in a separate, larger, publicly available database. Invasion may be a useful parameter in the histological grading and clinical management of hemangiopericytoma of the CNS.

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

“…The relationship between overall survival and tumor subtype, tumor size, and extent of resection did not reach statistical significance in this analysis. It should be noted that GTR vs. STR had reached statistical significance in our previous SEER analysis [11], but this was only after accounting for combined modality treatment with radiation. Information on extent of resection was not available for the majority of spinal tumors and was, therefore, not a major focus of this analysis.…”

“…It is important to note that one study did not find any benefit from GTR with regards to survival or recurrence [49]. Similarly, while radiotherapy has been found to improve local control and overall survival in CNS HPC [11,14,22,48], its role in spinal SFT/HPC is yet to be elucidated.…”

“…Those that have report conflicting results [7,9,14,18,19] with regards to classification, optimal management, and outcome. Prior literature has stratified SFT/HPC tumors by location [11,14,18,19] and demonstrated a correlation between infratentorial or posterior fossa location and outcome. However, no correlation between spinal location and clinical behavior has been previously recognized.…”

“…Information on extent of resection, however, is not routinely coded for spinal tumors. Certain variables, including invasiveness and metastasis at diagnosis [11] were only available for tumors diagnosed after 2004 and were, therefore, not included in the analysis. While patients in this series overlap with those in our previous published work [11,14] and in other SEER studies [20,22,41], we conducted this study using the latest SEER submission and all data extraction, coding, and analysis were conducted independently.…”

“…SFT and HPC are now known to demonstrate the NAB2-STAT6 fusion, which can be identified by immunohistochemistry [2][3][4][5][6]. Although these tumors are understood to share a biologic basis [7], they remain behaviorally distinct: SFTs occurring in the CNS tend to be classified as benign and are usually treated with resection alone [8,9], while HPCs are aggressive, known to metastasize systemically, and commonly recur [10][11][12][13]. HPCs of the CNS are frequently treated with adjuvant radiotherapy after resection [14,15].…”