Recurrence/Regrowth in Grade I Meningioma: How to Predict?

Area of Science:

• Neuro-oncology
• Molecular pathology
• Immunohistochemistry

Background:

• Grade I meningiomas are typically slow-growing tumors.
• Understanding the molecular markers associated with meningioma behavior is crucial for prognosis.
• Previous studies have explored various markers, but a definitive predictor for recurrence remains elusive.

Purpose of the Study:

• To investigate the relationship between the expression of specific molecules (HLA-G, HLA-E, Ki67, hormone receptors, p53, COX-2, HER2) and the biological behavior of grade I meningiomas.
• To determine if these markers can predict tumor recurrence or regrowth.
• To assess correlations between tumor size, peritumoral edema, calcifications, and marker expression.

Main Methods:

• Immunohistochemistry was performed on tissue microarrays from 96 patients with grade I intracranial meningiomas.
• Antibodies specific for HLA-G, HLA-E, Ki67, progesterone receptor (PR), estrogen receptor (ER), androgen receptor (AR), p53, COX-2, and HER2 were used.
• Tumor size, recurrence, peritumoral edema, and intratumoral calcifications were analyzed in relation to marker expression.

Main Results:

• High expression of HLA-G (100%) and COX-2 (100%), and significant expression of HLA-E (95.6%) and p53 (92.6%) were observed.
• Ki67 showed a higher median expression in recurrent meningiomas compared to primary ones (p=0.014), suggesting it as a recurrence biomarker.
• Tumor size correlated with peritumoral edema (p=0.031) and calcifications (p=0.018), but not with recurrence (p=0.486).

Conclusions:

• Ki67 is a potential biomarker for predicting recurrence/regrowth in grade I meningiomas.
• Tumor size is associated with edema and calcifications, but not directly with recurrence.
• Further research into the role of HLA molecules and hormone receptors in meningioma biology is warranted.