Seizures in patients with IDH-mutated lower grade gliomas

Purpose Since the introduction of the molecular definition of oligodendrogliomas based on isocitrate dehydrogenase (IDH)-status and the 1p19q-codeletion, it has become increasingly evident how this glioma entity differs much from other diffuse lower grade gliomas and stands out with longer survival and often better responsiveness to adjuvant therapy. Therefore, apart from using a molecular oligodendroglioma definition, an extended follow-up time is necessary to understand the nature of this slow growing, yet malignant condition. The aim of this study was to describe the long-term course of the oligodendroglioma disease in a population-based setting and to determine which factors affect outcome in terms of survival. Methods All adults with WHO-grade 2 oligodendrogliomas with known 1p19q-codeletion from five Scandinavian neurosurgical centers and with a follow-up time exceeding 5 years, were analyzed regarding survival and factors potentially affecting survival. Results 126 patients diagnosed between 1998 and 2016 were identified. The median follow-up was 12.0 years, and the median survival was 17.8 years (95% CI 16.0–19.6). Factors associated with shorter survival in multivariable analysis were age (HR 1.05 per year; CI 1.02–1.08, p < 0.001), tumor diameter (HR 1.05 per millimeter; CI 1.02–1.08, p < 0.001) and poor preoperative functional status (KPS < 80) (HR 4.47; CI 1.70–11.78, p = 0.002). In our material, surgical strategy was not associated with survival. Conclusion Individuals with molecularly defined oligodendrogliomas demonstrate long survival, also in a population-based setting. This is important to consider for optimal timing of therapies that may cause long-term side effects. Advanced age, large tumors and poor function before surgery are predictors of shorter survival. Graphical Abstract

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Differential gene expression underlying epileptogenicity in patients with gliomas

Mortazavi,

Khan,

Nieblas-Bedolla

et al. 2024

Neuro-Oncology Advances

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Background Seizures are a common sequela for patients suffering from gliomas. Molecular properties are known to influence the initiation of seizures that may influence tumor growth. Different levels of gene expression with seizures related to gliomas remain unclear. We analyzed RNA sequencing of gliomas to further probe these differences. Methods Total RNA sequencing was obtained from The Cancer Genome Atlas - Lower Grade Glioma project, comprised of 2021 WHO classification low grade gliomas, including IDH-mutant and IDH-wild type, to distinguish differential expression in patients who did and did not experience seizures. Utilizing QIAGEN Ingenuity Pathways Analysis, we identified canonical and functional pathways to characterize differential expression. Results Of 289 patients with gliomas, 83 (28.7%) had available information regarding seizure occurrence prior to intervention and other pertinent variables of interest. Of these, 50 (60.2%) were allocated to the seizure group. When comparing the level of RNA expression from these tumors between the seizure and non-seizure groups, 52 genes that were significantly differentially regulated were identified. We found canonical pathways that were altered, most significantly RhoGDI and Semaphorin Neuronal Repulsive signaling. Functional gene analysis revealed tumors that promoted seizures had significantly increased functional gene sets involving neuronal differentiation and synaptogenesis. Conclusions In the setting of gliomas, differences in tumor gene expression exist between individuals with and without seizures, despite similarities in patient demographics and other tumor characteristics. There are significant differences in gene expression associated with neuron development and synaptogenesis, ultimately suggesting a mechanistic role of a tumor-neuron synapse in seizure initiation .

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Seizures in patients with IDH-mutated lower grade gliomas

Cited by 5 publications

References 42 publications

Current and Future Drugs for Brain Tumors Treatment

Current and Future Drugs for Brain Tumors Treatment

Long-term follow up of patients with WHO grade 2 oligodendroglioma

Differential gene expression underlying epileptogenicity in patients with gliomas

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