Elsevier

World Neurosurgery

Volume 104, August 2017, Pages 795-801
World Neurosurgery

Original Article
Analysis of Prognostic Factors, Survival Rates, and Treatment in Anaplastic Hemangiopericytoma

https://doi.org/10.1016/j.wneu.2017.05.092Get rights and content

Objective

In this study, we aimed to identify prognostic factors in anaplastic hemangiopericytoma (AHPC) and clinical behaviors that differentiate primary and secondary AHPC.

Methods

The clinical data associated with 52 cases of AHPC that were surgically treated between 2008 and 2015 were reviewed. The patients were classified into the following 2 groups: primary AHPC (AHPC diagnosed at the first surgery) and secondary AHPC (malignant transformation from a lower-grade tumor).

Results

The study included 27 men and 25 women. The participants had a mean age of 43 years old. The 3- and 5-year progression-free survival (PFS) rates were 63.4% and 53.5%, respectively, and the corresponding overall survival rates were 78.7% and 70.9%, respectively. At the final follow-up, there were 22 (42.3%) recurrences, 4 (7.7%) extracranial metastases, and 11 (21.2%) deaths. On the basis of multivariate analysis, primary AHPC (hazard ratio [HR] = 0.293, 95% CI 0.122–0.705) and postoperative radiotherapy (PRT) (HR = 0.372, 95% confidence interval [CI] 0.148–0.932; P = 0.035) were significantly associated with increased PFS, and gross total resection (HR = 3.512, 95% CI 1.060–11.634; P = 0.040) and PRT (HR = 0.165, 95% CI 0.035–0.771; P = 0.022) were independent favorable factors for overall survival.

Conclusion

Gross total resection and PRT following surgery are recommended in AHPC. Identifying clinical behaviors that differentiate primary and secondary AHPC improved our understanding of this type of tumor and guided treatment strategies.

Introduction

Hemangiopericytoma (HPC) is a rare mesenchymal tumor that can occur in any part of the body. HPC was first described in 1942 by Stout and Murray, who proposed it was derived from pericytes, which are modified muscle cells.1 Because there was no clear difference between HPC and anaplastic hemangiopericytoma (AHPC) before 2007, both were described as “WHO grade II–III HPC.” As of 2007, the World Health Organization (WHO) classification for WHO grade II–III HPC recognizes 2 entities: HPC and AHPC.2 AHPCs are biologically aggressive tumors that have a high recurrence rate and poor tumor control.

It was previously shown that glioblastoma could present as either primary (the initial surgery was for glioblastoma) or secondary (progression from a lower-grade glioma),3 and the same course has also been reported for malignant meningioma, which can progress from a lower-grade meningioma or a benign meningioma.4 The concept of progression in HPC has not been previously explored, although we observed that HPC and AHPC clearly develop via a similar pathogenesis. Moreover, little information is available in the literature regarding clinical parameters, such as predictive factors and treatment regimens, for AHPC. In the present study, AHPC patients were classified into the 2 following groups: primary AHPC (the initial diagnosis was AHPC at the first surgery) and secondary AHPC (represented by malignant progression from a lower-grade tumor). We sought to determine whether these 2 groups display distinct clinical behaviors and to analyze the survival rates and factors that predict favorable outcomes in the hopes of providing guidance for the management of AHPC.

Section snippets

Patients

We reviewed 52 cases involving patients who were surgically treated for and pathologically diagnosed with AHPC. All patients were assessed to confirm the pathologic diagnosis. Tumors were classified according to the updated 2007 WHO classification criteria. Twelve patients received initial treatment in another hospital, and their data, including previous medical records, preoperative or postoperative radiography, pathology diagnosis, and treatment history, were retrospectively reviewed. All

Data in Patients with AHPC

In this study, we included 27 male patients (51.9%) and 25 female patients (48.1%). The average age at the time of the first AHPC surgery was 43 years old (range, 4–72 years old). The median preoperative KPS at the time of the initial operation was 90 (range, 50–90). The tumor locations were classified into the following 3 regions: supratentorial (n = 34, 65.4%), skull base (n = 12, 23.1%), and tentorial (n = 6, 11.5%). Symptoms depended mainly on the tumor location, and headache (n = 32,

Discussion

Intracranial HPC is an uncommon neoplasm that accounts for only 1% of all central nervous system tumors.5 In the 2007 WHO classification of brain tumors, HPC is divided into 2 subtypes: grade II (HPC) and grade III (AHPC).2 AHPC is characterized by the presence of >5 mitoses per 10 high-power fields and/or necrosis and must exhibit any 2 of the following traits: hemorrhage, moderate to high nuclear atypia, and moderate to high cellularity. Hemorrhage, necrosis, and cystic degeneration are

Conclusion

Surgery remains the first-choice treatment for AHPC, although extensive intraoperative blood loss increases its operative difficulty. Patients who received adjuvant radiotherapy following resection exhibited better local recurrence and had a higher OS rate. Clinical behaviors were distinct between the 2 groups. In particular, we found that secondary tumors were more likely to result in local recurrence and this increases our understanding of and guides treatment for AHPC.

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Conflict of interest statement: No financial interests or affiliations with institutions, organization, or companies are mentioned or have impacts on the views expressed in the article. There is no conflict of interest.

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