In this paper, researchers retrospectively assessed whether a biomarker of cellular proliferation (Ki-67) could be used to predict the clinical behavior of spheno-orbital meningiomas.

Study design

This was a single-center case review of 38 patients who underwent surgery for spheno-orbital meningioma with a minimum follow-up of 12 months. Tumor specimens were classified using the 2016 World Health Organization (WHO) tumor grades and examined for the presence of Ki-67 using immunohistochemistry.

Outcomes

Approximately 79% of tumors were WHO grade I with a mean Ki-67 of 3.8. WHO grade II (atypical) tumors made up 10.5% of lesions with an average Ki-67 of 14.9, while another 10.5% of tumors were grade III (anaplastic) with a mean Ki-67 of 58.3.

Statistically significant correlations existed between WHO grade and increasing Ki-67 index (P<0.001). The biomarker was also significantly correlated with disease progression (P<0.001). For patients with WHO grade I lesions, Ki-67 levels greater than or equal to 3.3 correlated with recurrence. Disease-specific mortality occurred in 13% of patients.

Limitations

The 2016 WHO classification update did not include Ki-67 immunohistochemistry results because there was considerable Ki-67 variability within each WHO grade. The authors found very little overlap of Ki-67 indices between tumor groups in this study, but there may be more overlap in a larger cohort. Furthermore, Ki-67 testing relies on some observer interpretation.

Clinical significance

Ki-67 immunohistochemistry testing can help predict meningioma behavior. The assessment may help determine which patients with WHO grade I tumors are at higher risk for meningioma recurrence.