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Adult glioblastoma with Lynch syndrome-associated mismatch repair deficiency forms a distinct high-risk molecular subgroup

  • 0NeuroMarkers, Houston, Texas, USA.
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January 21, 2025

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January 21, 2025

View abstract on PubMed

Summary

This summary is machine-generated.

A new glioblastoma subgroup, G3/MMR, characterized by mismatch repair gene mutations, exhibits significantly worse survival. Identifying these rare, aggressive tumors may improve patient outcomes and treatment strategies.

Area Of Science

  • Neuro-oncology
  • Genetics and Genomics
  • Cancer Biology

Background

  • Glioblastoma is the most common and lethal primary brain tumor.
  • Current molecular classifications aid in understanding glioblastoma heterogeneity.
  • Risk stratification is crucial for optimizing patient management.

Purpose Of The Study

  • To identify and characterize a novel high-risk glioblastoma subgroup.
  • To investigate the clinical and molecular features of this subgroup.
  • To explore potential therapeutic strategies for this aggressive subtype.

Main Methods

  • Analysis of a prospective cohort of 218 glioblastoma patients.
  • Germline mutation analysis for mismatch repair (MMR) genes.
  • Integrated clinical, histological, and molecular profiling of identified tumors.
  • Immunohistochemistry for p53 and MMR proteins, and multinucleated giant cells (MGCs).

Main Results

  • Five patients with germline MMR gene mutations (Lynch syndrome) identified.
  • This G3/MMR subgroup showed significantly worse median survival (3.25 months post-surgery).
  • Distinct clinical and molecular features identified, including high tumor mutation burden (TMB) and specific genetic alterations (e.g., *MSH2*, *MSH6*, *TP53*, *PIK3CA*, *PTEN*).
  • Multinucleated giant cells (MGCs) and p53 positivity were associated with G3/MMR tumors.

Conclusions

  • A distinct, high-risk G3/MMR glioblastoma subgroup associated with Lynch syndrome has been identified.
  • Specific clinical and molecular markers can help identify these aggressive tumors.
  • One G3/MMR patient demonstrated a significant survival benefit with nivolumab-ipilimumab, suggesting potential efficacy of immune checkpoint inhibitors.

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