Introduction: A putative role for progesterone in the growth of meningioma has been suggested. The aim of this study was to attest the role of progesterone receptor (PR) in predicting the biological behaviour of meningioma.
Materials and methods: The immunohistochemical expression of PR in meningioma was studied. Cell kinetic using the Ki-67/MIB-1 labelling index (LI) was evaluated and correlated to PR expression.
Results: This study included 30 cases of meningioma, 15 (50%) recurrent and 15 (50%) nonrecurrent. PR expression was significantly more common in benign meningioma (BM) than atypical meningioma (AM) and malignant meningioma (MM). The mean Ki-67/MIB-1 LI was significantly the highest in MM, high in AM and lowest in BM. In PR-negative meningioma, the mean Ki-67/MIB-1 LI was significantly higher compared with PR-positive meningioma. In the recurrent group, PR was more frequently immunonegative and the mean Ki-67/MIB-1 LI was higher than that in the nonrecurrent group. The difference in PR expression between nonrecurrent and recurrent cases was significant only in BM. The difference in Ki-67/MIB-1 LI was significant only when the recurrent meningioma was compared with nonrecurrent tumour, irrespective of the grade.
Conclusion: BM expresses PR more than AM and MM. The absence of this expression in BM implies a likely risk for recurrence. Ki-67/MIB-1 LI is valuable to predict tumour grade and the overall risk of recurrence. However, it must be interpreted with caution in BM.