Prognostic Factors for Survival in Adult Patients with Cerebral Low-Grade Glioma

Abstract

Low grade gliomas (LGGs) account for approximately 5-10% of the primary CNS tumors diagnosed in USA each year [1]. Historically, histological classification of these tumors was either pure/mixed astrocytomas, or oligodendrogliomas. In 2021, WHO revised 5th edition classification groups IDH-mutant diffuse astrocytic tumors together in one type (Astrocytoma, IDH-mutant), and oligodendrogliomas into (Oligodendroglioma, IDH-mutant, and 1p/19q-codeleted). Also, the new classification system uses the category “Circumscribed astrocytic gliomas” for other circumscribed astrocytic tumors (pilocytic astrocytomas, pleomorphic xanthoastrocytomas and subependymal giant cell astrocytomas) [2]. Molecular biology and genetics helped understanding the tumor behavior for better defining subgroups at increased risk of recurrence, WHO grade II tumors are subdivided into three classes [3]: 1) oligodendroglioma (1p/19q codeleted tumors) 2) IDH-mutated non-1p/19q codeleted astrocytoma 3) IDH wild-type astrocytoma