Surgical management of lower-grade glioma in the spotlight of the 2016 WHO classification system

• Published in: Journal of neuro-oncology Vol. 141; no. 1; pp. 223 - 233
• Main Authors: Delev, Daniel, Heiland, Dieter Henrik, Franco, Pamela, Reinacher, Peter, Mader, Irina, Staszewski, Ori, Lassmann, Silke, Grau, Stefan, Schnell, Oliver
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-01-2019; Springer Nature B.V
• Subjects: Adolescent; Adult; Biopsy; Brain Neoplasms - classification; Brain Neoplasms - genetics; Brain Neoplasms - surgery; Brain tumors; Chemotherapy; Child; Chromosome Deletion; Chromosomes, Human, Pair 1 - genetics; Chromosomes, Human, Pair 19 - genetics; Classification; Clinical Study; Glioma; Glioma - classification; Glioma - genetics; Glioma - surgery; Humans; Isocitrate Dehydrogenase - genetics; Kaplan-Meier Estimate; Medicine; Medicine & Public Health; Middle Aged; Mutation; Neurology; Oncology; Patients; Retrospective Studies; Survival; Treatment Outcome; Tumors; World Health Organization; Young Adult; mutation; 1p/19q; Gross total resection; Lower-grade gliomas; WHO-classification; Astrocytoma; Oligodendroglioma; IDH-mutation
• ISSN: 0167-594X; 1573-7373
• DOI: 10.1007/s11060-018-03030-w

Purpose
According to the 2016 WHO classification lower-grade gliomas consist of three groups:
IDH-
mutated and 1p/19q co-deleted,
IDH-
mutated and
IDH-
wildtype tumors. The aim of this study was to evaluate the impact of surgical therapy for lower-grade gliomas with a particular focus on the molecular subgroups.
Methods
This is a bi-centric retrospective analysis including 299 patients, who underwent treatment for lower-grade glioma between 1990 and 2016. All tumors were re-classified according to the 2016 WHO classification. Data concerning baseline and tumor characteristics, overall survival, different treatment modalities and functional outcome were analyzed.
Results
A total of 112 (37.5%) patients with
IDH
-mutation and 1p/19q co-deletetion, 86 (28.8%) patients with
IDH
-mutation and 101 (33.8%) patients with
IDH
-wildtype tumors were identified. The median overall survival (mOS) differed significantly between the groups (p < 0.001). Surgical resection was performed in 226 patients and showed significantly improved mOS compared to the biopsy group (p = 0.001). Gross total resection (GTR) was associated with better survival (p = 0.007) in the whole cohort as well as in the
IDH
-mutated and
IDH
-wildtype groups compared to partial resection or biopsy.
IDH
-wildtype patients presented a significant survival benefit after combined radio-chemotherapy compared to radio- or chemotherapy alone (p = 0.02). Good clinical status (NANO) was associated with longer OS (p = 0.001).
Conclusion
The impact of surgical treatment on the outcome of lower-grade gliomas depends to a great extent on the molecular subtype of the tumors. Patients with more aggressive tumors (
IDH-
wildtype) seem to profit from more intensive treatment like GTR, multiple resections and combined radio-/chemotherapy.