The role of clinical factors and immunocheckpoint molecules in the prognosis of patients with supratentorial extraventricular ependymoma: a single-center retrospective study

Liguo Wang,Song Han,Zhiqiang Li,Yakun Yang,Zuocheng Yang,Changxiang Yan

doi:10.1007/s00432-020-03425-1

Abstract

PurposeSupratentorial extraventricular ependymoma (SEE) is a rare subset of ependymomas located in the supratentorial parenchyma, and little is known regarding its management and prognosis. Our study aimed to reveal the prognostic factors in patients with SEE and the roles of programmed death ligand-1 (PD-L1), programmed cell death protein 1 (PD-1), Ki-67, and neural cell adhesion molecule L1 (L1CAM) in predicting these patients’ outcomes.MethodsWe retrospectively studied the clinical features and prognostic factors in 48 patients with SEE admitted to our center from April 2008 to October 2018. Tissue slides were constructed from patient samples, and PD-L1, PD-1, Ki-67, and L1CAM expression levels were evaluated by immunohistochemistry.ResultsPatients with gross total resection (GTR) had better progression-free survival than patients with subtotal resection (STR). Moreover, the recurrence hazard ratios in patients with STR at 3, 5, and 10 years were 8.746, 6.866 and 3.962 times those of patients with GTR, respectively. PD-L1 positivity predicted worse progression-free survival, while the recurrence hazard ratios for patients with PD-L1 positivity at 3, 5, and 10 years were 10.445, 5.539, and 3.949 times those of patients with PD-L1 negativity, respectively. Multivariate analysis revealed that PD-L1 expression and GTR could independently predict outcomes in patients with SEE.ConclusionPD-L1 expression was an independent and more readily obtained predictor of outcomes, representing a simple and reliable biological prognostic factor for patients with SEE. Further studies are needed to explore PD-L1 inhibitor treatment for patients with ependymoma.Clinical trial registrationNo clinical trials were performed in the study.

Highlights

Ependymomas are rare neoplasms of the central nervous system (CNS), accounting for 3.14% of all CNS tumors or 3–9% of all intracranial glial neoplasms (Chen et al 2013)
We aimed to investigate the prognostic factors in patients with Supratentorial extraventricular ependymoma (SEE) and the roles of programmed death ligand-1 (PD-L1), programmed death receptor-1 (PD-1), Ki-67, and L1CAM in predicting these patients’ outcomes
Our results showed no correlation between L1CAM expression and World Health Organization (WHO) histologic grading by the Spearman regression method (r = 0.053, P = 0.721)

Summary

Introduction

Ependymomas are rare neoplasms of the central nervous system (CNS), accounting for 3.14% of all CNS tumors or 3–9% of all intracranial glial neoplasms (Chen et al 2013). The reported prognostic factors of ependymoma include age, tumor location, histological grade, the extent of resection (EOR), metastatic spread, Ki-67 status, and adjuvant radiotherapy (Metellus et al 2007; Kuncova et al 2009; Merchant et al 2009; Pejavar et al 2011; Tarapore et al 2013; Sayegh et al 2014). The subtype (ependymoma, RELA fusion-positive) was included in the identification of ependymas for the first time in the classification of CNS tumors by the WHO in 2016 (Reni et al 2017). Neural cell adhesion molecule L1 (L1CAM), one of the protein products of the RELA fusion gene, is of interest, and Nambirajan and Witt reported that programmed death ligand-1 (PD-L1) is upregulated in ST-RELA ependymomas (Witt et al 2018; Nambirajan et al 2019). We aimed to investigate the prognostic factors in patients with SEE and the roles of PD-L1, programmed death receptor-1 (PD-1), Ki-67, and L1CAM in predicting these patients’ outcomes

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