Related Experiment Video
Updated: Jul 6, 2025
Evaluation of Biomarkers in Glioma by Immunohistochemistry on Paraffin-Embedded 3D Glioma Neurosphere Cultures
Published on: January 9, 2019
SOMATIC DEFICIENT MISMATCH REPAIR ASSESSED BY IMMUNOHISTOCHEMISTRY AND CLINICAL FEATURES IN BRAZILIAN GLIOBLASTOMA
C A F Yamada1,2,3, S M F Malheiros4, L L F Do Amaral1,3
1Hospital Beneficência Portuguesa de São Paulo, São Paulo, Brazil.
Background:
Glioblastoma (GBM) is the most frequent primary malignant CNS tumor. Deficient mismatch repair (dMMR) is associated with better prognosis and is a biomarker for immunotherapy. Evaluation of MMR by immunohistochemistry (IHC) is accessible, cost effective, sensitive, and specific.
Aim:
Our objective was to investigate MMR proteins in adult GBM patients.
Materials And Methods:
We retrospectively analyzed 68 GBM samples to evaluate the proficiency of MMR genes expression assessed by IHC. Clinicopathologic and molecular features were compared in proficient (pMMR) or dMMR.
Results:
10 (14.7%) samples showed dMMR, and the most frequent was MSH6 (100%) followed by MSH2, PMS2, and MLH1. We observed heterogeneous expression of dMMR in 5 GBMs. The median overall survival did not differ between pMMR (19.8 months; 0.2-30) and dMMR (16.9 months; 6.4-27.5) (p = 0.31). We observed a significantly higher overall survival associated with gross total resection compared to subtotal resection or biopsy (30.7 vs. 13.6 months, p = 0.02) and MGMT methylated status (29.6 vs. 19.8 months, p = 0.049). At the analysis time, 10 patients were still alive, all in the pMMR group.
Conclusions:
Our data demonstrated dMMR phenotype assessed by IHC in an expressive portion of GBM patients, however without significant impact on overall survival.
