Clinical Features and Long-Term Outcome of Primary Intracranial Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumors: 14 Cases From a Single Institution

Abstract

Objective: Primary intracranial Ewing sarcoma (ES)/peripheral primitive neuroectodermal tumors (pPNETs) are extremely rare, and only a few studies have reported >4 cases of this disease. The purpose of this study was to explore the clinical features, treatment, and outcome of primary intracranial ES/pPNETs.

Methods: The clinical data of 14 patients who had been surgically treated from February 2003 to November 2017 and in whom immunohistochemical staining results had confirmed the diagnosis of primary intracranial ES/pPNETs were retrospectively analyzed. Kaplan-Meier survival analysis was used to estimate the survival rate and the median survival time (MST).

Results: Gross total resection (GTR) was achieved in 7 cases, and subtotal resection was performed in 7 cases. During follow-up, 10 (71.4%) patients had local recurrence and 3 (21.4%) patients had distant metastasis. The overall 1-, 2-, and 5-year survival rates were 78.6%, 47.6%, and 19.0%, respectively. Kaplan-Meier survival analysis showed that postoperative radiotherapy was a significant prognostic factor for longer MST (P = 0.034). GTR and radiotherapy with or without adjuvant chemotherapy yielded the highest 2-year survival rate (100%). Three patients who underwent GTR, radiotherapy, and chemotherapy had the highest 2-year survival rates (100%) and the longest MST (48 months).

Conclusions: Primary intracranial ES/pPNETs have an aggressive clinical course, with a high tendency for local recurrence and distant metastasis. Radiotherapy plays a significant role in improving the survival of patients. GTR combined with radiotherapy and chemotherapy may be the most beneficial treatment modality.

Keywords: Ewing sarcoma; Intracranial; Primitive neuroectodermal tumors; Treatment.