Impact of epidemiological characteristics of supratentorial gliomas in adults brought about by the 2016 world health organization classification of tumors of the central nervous system

Abstract

The latest World Health Organization (WHO) classification of tumors of the central nervous system (CNS) integrates both histological and molecular features in the definition of diagnostic entities. This new approach enrolls novel entities of gliomas. In this study, we aimed to reveal the epidemiological characteristics, including age at diagnosis, gender ratio, tumor distribution and survival, of these new entities. We retrospectively reclassified 1210 glioma samples according to the 2016 CNS WHO diagnostic criteria. In our cohort, glioblastoma multiforme (GBM) with wildtype isocitrate dehydrogenase (IDH) was the most common malignant tumor in the brain. Almost all gliomas were more prevalent in males, especially in the cluster of WHO grade III gliomas and IDH-wildtype GBM. Age at diagnosis was directly proportional to tumor grade. With respect to the distribution by histology, we found that gliomas concurrent with IDH-mutant and 1p/19q-codeleted or with single IDH-mutant were mainly distributed in frontal lobe, while those with IDH-wildtype were dominant in temporal lobe. Lesions located in insular lobe were more likely to be IDH-mutant astrocytoma. In summary, our results elucidated the epidemiological characteristics as well as the regional constituents of these new gliomas entities, which could bring insights into tumorigenesis and personalized treatment of Chinese glioma population.

Keywords: classification; epidemiology; gliomas; impact.

Figure 1. The survival rate and specific distribution of 2007/2016 CNS WHO pathology entities

I. Kaplan-Meier estimates of survival time in 2007/2016 CNS WHO pathology entities. Both the 2007 and 2016 CNS WHO could categorized patients into eight entities with different survival. II. Distribution of diagnostic entities in the 2007 CNS WHO (N=1210). GBM was the most frequently reported malignant tumor in the brain, which accounted for 25.0% of all the glioma. III. Distribution of diagnostic entities in the 2016 CNS WHO (N=1210). GBM with IDH-wildtype was the most common malignant tumor in the brain, which accounted for 27.0% of all the glioma.

Figure 2. Regional constituents of pathological entities and preferential distribution of different tumor subtypes

I. Composing proportion of pathological entities in the frontal, temporal, insular and other brain sites. The predominant proportion in frontal, temporal and insular lobe was IDH-mutant and 1p/19q-codeleted O, IDH-wildtype GBM and IDH-mutant A, respectively. II-V. Almost 76.0% gliomas occurred in frontal and temporal lobe. Patients concurrent with IDH-mutant and 1p/19q-codeleted or with single IDH-mutant were mainly distributed in frontal lobe, while those with IDH-wildtype were dominant in temporal lobe.