Glioma Subclassifications and Their Clinical Significance

Abstract

The impact of targeted therapies in glioma has been modest. All the therapies that have demonstrated a significant survival benefit for gliomas in Phase III trials, including radiation, chemotherapy (temozolomide and PCV [procarbazine, lomustine, vincristine]), and tumor-treating fields, are based on nonspecific targeting of proliferating cells. Recent advances in the molecular understanding of gliomas suggest some potential reasons for the failure of more targeted therapies in gliomas. Specifically, the histologic-based glioma classification is composed of multiple different molecular subtypes with distinct biology, natural history, and prognosis. As a result of these insights, the diagnosis and classification of gliomas have recently been updated by the World Health Organization. However, these changes and other novel observations regarding glioma biomarkers and subtypes highlight several clinical challenges. First, the field is faced with the difficulty of reinterpreting the results of prior studies and retrospective data using the new classifications to clarify prognostic assessments and treatment recommendations for patients. Second, the new classifications and insights require rethinking the design and stratification of future clinical trials. Last, these observations provide the essential framework for the development and testing of new specific targeted therapies for particular glioma subtypes. This review aims to summarize the current literature regarding glioma subclassifications and their clinical relevance in this evolving field.

miR‐128‐3p contributes to mitochondrial dysfunction and induces apoptosis in glioma cells via targeting pyruvate dehydrogenase kinase 1

“…Glioma, the most common type of intracranial neoplasm, accounting for more than 50%, is characterized by prominent heterogeneity, rapid proliferation, and extensive invasion of brain tissue . Glioma is also one of the most malignant human brain tumors with high morbidity and low survival rates.…”

Nucleolar and spindle‐associated protein 1 is a tumor grade correlated prognosis marker for glioma patients

“…Gliomas are the most prevalent primary tumors of the central nervous system (CNS) with certain glial cell‐like characteristics . According to pathologic evaluation, gliomas are classified into four grades from Grade I to IV, depending on which the survival time of glioma patients varies strikingly .…”

Cerebellopontine Angle Anaplastic Ependymoma: A Case Report and Literature Review

“…One hypothesis regarding oncogenesis of intracranial extra-axial epedymomas has been proposed and favored by most studies on the basis of the relationship between the lesion and subarachnoid space: intracranial extra-axial epedymomas derive from ectopic ependymal nests that result from migration disorders of the germinal matrix. According to the 2016 WHO classification of CNS neoplasms, ependymal tumors are being classified as WHO grade I: myxopapillary ependymoma (occurring almost exclusively in the conus-cauda-filum terminale region) and subependymoma, a benign, slowly growing intraventricular lesion with a very favourable prognosis, WHO grade II ependymoma and WHO grade III anaplastic ependymoma (Chen, 2017). Although most ependymal tumors are benign, Grade III ependymomas are characterised by hypercellularity, cellular and nuclear pleomorphism, frequent mitosis, pseudopalisading necrosis and endothelial proliferation an associated with higher risk of recurrence, or drop metastasis (Trivedi, 2017;Ferris, 2017;Sun, 2017;Takeda, 2017).…”