The role of the Ki-67 labelling index as an independent prognostic factor in indonesian glioma patients

Abstract

Introduction. Gliomas are the most common type of brain tumor. However, interpreting glioma morphology is subjective, and identifying mitosis can be challenging. This can impact the determination of the patient's tumor grade, therapy, and prognosis. In addition, the Ki-67 expression level, which reflects the tumor cells' ability to proliferate, is closely related to the patient’s survival. This study aims to find a correlation between Ki-67 expression and the overall survival (OS) of glioma patients in the Indonesian population. Methods. Ninety-one glioma patients from Sardjito General Hospital were collected for formalin-fixed embedded paraffin (FFPE) samples, and the Ki-67 labeling index (LI) was calculated by determining the percentage of labeled nuclei per 1000 cells using a 40x objective lens in a randomized area (average method). The OS was calculated from the day of pathology diagnosis until death or the last follow-up (for censored cases). Kaplan-Meier survival analysis was used to analyze the OS. Results. Individuals aged ≥60 with high-grade tumors, infratentorial gliomas, and a Ki-67 LI ≥10% had a shorter OS. The p-values associated with these factors were 0.001, 0.018, and 0.006, respectively. In multivariate analysis, age and tumor grade did not significantly correlate with OS. Conclusion. Glioma patients with a Ki-67 LI ≥10% have a significantly shorter OS than those with a lower Ki-67 LI, indicating that Ki-67 LI is an independent prognostic factor in Indonesian glioma patients.