PD-L1 Immunohistochemistry as a Surrogate Marker in Meningioma

This is the authors' abstract. We don't add key points for this paper.

Background: Meningioma is a common central nervous system (CNS) tumor originating from arachnoid cells, generally benign but aggressive in higher grades. Emerging studies highlight the programmed cell death protein 1 and programmed death-ligand 1 (PD-L1) pathway as crucial for tumor immune evasion, frequently linked to worse outcomes. While surgery remains the standard treatment, immunotherapy may show potential for complex and recurrent meningiomas. Material and Methods: This study collected intracranial meningioma cases from 2017 to 2021, analyzing tissue blocks for PD-L1 expression and reclassifying tumors per the 2021 World Health Organization CNS guidelines. Clinical data were documented simultaneously. Data were recorded in Excel and analyzed with Statistical Package for the Social Sciences, using Chi-square tests to assess correlations between PD-L1 levels and clinical features. Result: The study, involving 50 cases with 36% showing PD-L1 positivity, revealed that PD-L1 expression in meningiomas is significantly associated with age ( χ 2 = 17.22, df = 4, P = 0.003), tumor subtype ( χ 2 = 16.797, df = 7, P = 0.022), tumor grade ( χ 2 = 13.590, df = 2, p <0.001), and brain invasion ( χ 2 = 14.470, df =1, P <0.001). Higher PD-L1 expression was more prevalent in higher-grade tumors (88.9% in grade 2) and cases with brain invasion (38.9%). No significant associations were observed with gender, tumor location, bone involvement, or recurrence ( P >0.05). Conclusion: This study reveals that PD-L1 is associated with tumor aggressiveness in meningiomas, especially in higher-grade and invasive cases, highlighting its potential as a key target for personalized immunotherapy to improve treatment outcomes.