Therapeutic Strategy for Glioma Grade Ⅱ/Ⅲ

Abstract

  Glioma grade Ⅱ/Ⅲ consists of various diseases based on the WHO 2016 molecular classification, and a large percentage of these diseases comprise oligodendroglial tumors harboring chromosome 1p/19q codeletion, IDH-mutant astrocytic tumors, and IDH-wild type diffuse gliomas. Since the tumor characteristics of these molecular subtypes differ, there is a need to establish a standard therapy optimized for each disease. This review presents current evidence and recommended standard therapy for grade Ⅱ/Ⅲ gliomas, and discusses several issues that must be considered. For example, a randomized phase Ⅲ study of primary high-risk, low-grade gliomas recently showed that postoperative radiotherapy and adjuvant PCV chemotherapy are effective. However, careful observation might be still an option for low-risk gliomas. Therefore, it is important to identify the factors related to tumor malignancy for each molecular subtype and determine the risk of individual tumors being affected by such factors, and then establish standard treatment strategies according to the risk categories for each disease.