Evaluation Of Surrogate Markers to Define H3 G34R/V-Mutant Gliomas

Abstract

Background: H3 G34-mutant glioma was a new high-grade glioma, characterized by mutation of histone3.3 codon34. Currently, standard gene sequencing methods are helping in tumor diagnosis, but less expensive and faster H3 G34R/V staining method has not been studied yet in Thailand. Objectives: The purpose of this research is to find surrogate makers for diagnosing this tumor by uncomplicated immunohistochemical method. Methods: Formalin-fixed and paraffin-embedded tissue samples of 30 diffuse hemispheric gliomas were collected H3 G34R, H3 G34V, Olig2, p53 were evaluated using immunohistochemistry. Comparisons of immunohistochemical method and sequencing standard technique were made. Cost-effectiveness was analyzed. Results: Two cases of H3 G34-mutant gliomas were confirmed by mutation analysis. One case was positive for H3 G34V antibody (1/1) while another case was negative for H3 G34R (0/1). The cost-effectiveness showed that the sequencing technique prolonged turnaround time but gave a cost saving 23 USD (17%). Conclusions: G34R and G34V antibodies are not sensitive surrogate markers for diagnosing H3.3 G34-mutant gliomas. However, more samplings are yet to be tested in the future.