Correlation of Ki-67 and E-cadherin expression with tumor grade and brain invasion in meningiomas.

Objectives: Meningioma is most common primary brain tumor. Meningiomas with brain invasion or higher WHO grade behave more aggressively. The objective of this study was to investigate whether Ki-67 and E-cadherin immunohistochemical markers can be utilized to identify high grade tumors bearing potential for brain invasion. Methodology: It was a comparative cross-sectional study conducted at Armed Forces Institute of Pathology (AFIP), Rawalpindi from 15 April 2025 to 15 November 2025. Eighty-five cases were included in the study. Immunohistochemistry was performed and analyzed for Ki-67 index and E-cadherin expression (Hscore and categorical groups: low/moderate/strong). Immunohistochemistry markers were compared across brain invasion status and WHO grades using nonparametric tests. ROC and bivariable model were used to calculate the discriminative strengths of these biomarkers. Correlations were assessed using Spearman's method. Chi-square test was employed to identify significance of association. Results: Ki-67 index was significantly higher in invasive tumors (p < 0.001) and gradually increased with increasing grade of tumor (p < 0.001). Ki-67 showed significant discriminative ability for brain invasion. Categorical analysis of E-cadherin (based on H-score categorical groups) was also significantly associated with brain invasion (p = 0.002) and grade (p < 0.001). Conclusions: Ki-67 index and E-cadherin categories strongly correlates with tumor potential of brain invasion and higher WHO grades thus aiding in identifying aggressive meningiomas. Categorical E-cadherin reporting enhances its utility over continuous H-scores alone. Thus, even in the absence of glial tissue in biopsy specimen, these biomarkers may help to suggest invasive nature of tumor in appropriate clinical context.