Oligodendroglioma

O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation is an important biomarker because it is associated with reduced DNA repair capacity and increased sensitivity to alkylating agents, particularly temozolomide (TMZ)...Because MGMT methylation is biologically continuous, this review further argues that borderline results should be reported as gray-zone or intermediate categories when validated, and that quantitative methylation values should be integrated into subtype-aware multivariable models rather than being reduced exclusively to binary calls. This review summarizes the biological and clinical relevance of MGMT promoter methylation across glioma subtypes and proposes a subtype-aware, treatment-conditional, and assay-aware framework for interpreting its predictive and survival-related significance.

This case underscores that metachronous collision tumors can arise without radiotherapy, necessitating histopathological and molecular integration for accurate diagnosis. Long-term vigilance is critical for detecting sequential tumors, and shared microenvironments or genetic pathways may underlie tumorigenesis. Comprehensive profiling aids in clarifying pathogenesis and guiding management. https://thejns.org/doi/10.3171/CASE26149.

Overall, these data describe subtype-specific patterns of m6A marking and isoform architecture across glioma tissues, derived from computational inference using direct RNA sequencing in a modestly sized cohort and warrant validation by orthogonal methods in larger studies. These findings are consistent with concurrent independent evidence that isoform-specific m6A deposition is evolutionarily conserved across mammals and that long-read isoform resolution reveals transcript diversity in glioma not captured by gene-level analysis. While cohort size and the absence of orthogonal site-level validation suggest that the data require cautious interpretation, this work provides a hypothesis-generating resource and methodological framework for future mechanistic and translational investigation of the glioma epitranscriptome.

P1/2, N=30, Recruiting, Aveta Biomics, Inc. | Trial completion date: Jan 2026 --> Jun 2027 | Trial primary completion date: Dec 2025 --> Dec 2026

Compared to supratentorial tumors, non-R132H IDH1 mutations are significantly more frequent in infratentorial tumors. IDH2-mutant gliomas almost exclusively occur in adults and in supratentorial locations, with a significantly higher proportion in oligodendrogliomas than astrocytoma.

P1, N=24, Not yet recruiting, Megan Mantica

The detection of 1p19q co-deletion in other tumors and its peculiar relationship with MGMT methylation made us think of the complexity of tumor biology and how both genetic and epigenetic factors interplay to influence tumor behavior and response to therapy.

P3, N=57, Active, not recruiting, Servier | Trial primary completion date: Oct 2025 --> May 2026

P1, N=60, Completed, Case Comprehensive Cancer Center | Active, not recruiting --> Completed

Oligo Cdkn2a tumors displayed metabolic and transcriptional changes associated with IDH and CIC mutations, and single cell sequencing identified a bias towards oligodendrocyte differentiation compared to an IDH wild-type glioblastoma mouse model. Oligo Cdkn2a tumors represent the first mouse model system to recapitulate the genetic, histological and transcriptional features of human IDH-mutant 1p/19q-codeleted oligodendrogliomas, offering a platform to further dissect tumor biology and test new therapeutic strategies.

Second, increased mesenchymal-like-state abundance occurred independently of acquired genetic alterations and instead coincided with elevated macrophage expression. Overall, our findings provide an integrative model that traces the cell intrinsic and extrinsic factors that shape cellular states during IDH-mutant glioma disease progression.

P1, N=3, Terminated, University of Rochester | N=30 --> 3 | Active, not recruiting --> Terminated; lack of enrollment