Prognostic Biomarkers in Isocitrate Dehydrogenase Wild-Type Glioblastoma: A Focus on B7-H3

Isocitrate dehydrogenase (IDH) wild-type (wt) glioblastoma is an aggressive malignancy associated with poor clinical outcomes, marked by high heterogeneity and resistance to treatment. This study aims to investigate the prognostic significance of B7-H3 expression in IDH wt glioblastoma and its potential association with clinical outcomes, including overall survival (OS) and progression-free survival (PFS). Additionally, the relationship between B7-H3 and PD-L1 expression was explored.

A retrospective cohort of 86 IDH wt glioblastoma patients, all of whom underwent surgery, radiotherapy, and temozolomide treatment, was analyzed. B7-H3 expression was quantified using an immunoreactivity score (IRS), classifying samples as low (IRS ≤ 4) or high (IRS > 4). PD-L1 expression was evaluated based on tumor and immune cell staining, with >5% positivity indicating significant expression.

High B7-H3 expression was significantly associated with poorer OS and PFS. Co-expression of B7-H3 and PD-L1 was prevalent, particularly among younger male patients with unifocal tumors; however, PD-L1 expression did not show a significant correlation with clinical outcomes.

B7-H3 appears to be a promising prognostic biomarker in IDH wt glioblastoma and may serve as a target for developing combination therapies, integrating B7-H3-targeting treatments with immune checkpoint inhibitors. Further prospective studies are necessary to validate these findings and to explore potential therapeutic strategies.