B7-H3 as a Reliable Diagnostic Biomarker for the Differentiation of High-Grade Gliomas (HGGs) and Low-Grade Gliomas (LGGs)

Background/Objectives: This study aimed to evaluate the diagnostic and prognostic utility of B7-H3 expression in differentiating low-grade gliomas (LGGs) from high-grade gliomas (HGGs) and to examine its association with clinical outcomes. Methods: This retrospective study included 99 patients with histopathologically confirmed gliomas (42 LGGs and 57 HGGs). B7-H3 expression was assessed using immunohistochemistry and scored by immunoreactive score (IRS). Results: B7-H3 expression was significantly higher in HGG compared to LGG (p < 0.001). The total IRS (B7-H3 A × B) demonstrated strong discriminative power (AUC = 0.816). High B7-H3 expression independently predicted disease progression (OR = 4.9, 95% CI: 2.4–10.1; p < 0.001) and was associated with IDH wild-type status and elevated Ki-67 index. Patients with high B7-H3 had significantly shorter overall survival (median 6 months vs. 42 months) and progression-free survival (median 3 months vs. 25 months) (both p < 0.001). Cox regression confirmed high B7-H3 as an independent predictor of mortality (HR = 2.9, 95% CI: 1.7–4.7; p < 0.001) and progression (HR = 2.6, 95% CI: 1.6–4.2; p < 0.001). Conclusions: B7-H3 expression is a reliable biomarker for distinguishing HGG from LGG and is independently associated with worse survival outcomes. Its assessment may aid in glioma classification and prognostication.