A comparison of CDKN2A status in gliomas using different techniques: The loss of p16 as a surrogate marker

Arnault Tauziède-Espariat ¹, Audrey Rousseau ^2,3, Laetitia Basset ^2,3

⁰Department of Neuropathology, GHU Paris-Psychiatrie et Neurosciences, Sainte-Anne Hospital, Paris, France.

Journal of Neuropathology and Experimental Neurology +

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May 30, 2025

View abstract on PubMed

Summary

SNP array is the most reliable method for detecting CDKN2A homozygous deletions in CNS tumors. p16 immunohistochemistry serves as an accurate surrogate biomarker for this critical genetic alteration.

Area Of Science

Neuro-oncology
Molecular Diagnostics
Cancer Genetics

Background

The CDKN2A homozygous deletion (HD) is crucial for diagnosing and predicting prognosis in CNS tumors.
Accurate molecular diagnostics are essential for assessing CDKN2A status.

Purpose Of The Study

To evaluate the concordance of FISH, NGS, and SNP array for CDKN2A HD detection in adult-type gliomas.
To compare these molecular techniques with p16 and MTAP immunostainings.

Main Methods

Analysis of a cohort of 40 adult-type gliomas.
Utilized FISH, NGS, and SNP array for CDKN2A deletion assessment.
Performed p16 and MTAP immunohistochemistry.

Main Results

SNP array demonstrated the highest reliability for detecting CDKN2A HD.
p16 immunohistochemistry (IHC) accurately surrogates biallelic CDKN2A inactivation.
p16 IHC outperformed MTAP IHC, identifying CDKN2A HD gliomas with intact MTAP.
IHC detected hemizygous deletions with secondary molecular events like promoter hypermethylation.

Conclusions

SNP array is the most dependable technique for CDKN2A HD.
p16 IHC is a reliable biomarker for detecting CDKN2A HD in CNS tumors.

Keywords:

CDKN2A FISH MTAP SNP array comparison gliomas next-generation sequencing (NGS) p16 immunohistochemistry