Detection of progesterone receptor and the correlation with Ki-67 labeling index in meningiomas

Although most of the meningiomas are benign, some of them are associated with a less favorable clinical outcome. The major prognostic question regarding meningiomas is the prediction of recurrence which is largely dependent on the histopathological type, grading, proliferation indices and progesterone receptor status.

Our study was done to assess the expression of Ki-67 and progesterone receptor (PR) in different histological types, grades, recurrent and non-recurrent meningiomas.

A total of 60 cases were collected over a period of 2.5 years. Hematoxylin and eosin staining was done for histological typing and grading of the tumors. Immunohistochemical staining was done for Ki-67 and PR using standard immunoperoxidase technique and Ki-67 Labeling Index (LI) and PR score was calculated.

Mean Ki-67 LI was significantly higher in males versus females, in Grade II versus Grade I, in recurrent versus non-recurrent and in PR-negative versus PR-positive meningiomas. Moreover, considering Grade I and Grade II-meningiomas separately, mean Ki-67 LI was significantly higher in recurrent cases. PR positivity was significantly higher in females versus males, in Grade I versus Grade II and in non-recurrent versus recurrent meningiomas. Correlation between Ki-67 LI and PR expression was also evaluated and a strong inverse correlation was found between Ki-67 LI and PR expression. A strong negative correlation was also established between the values of Ki-67 LI and recurrence-free survival.

Our results establish that the immunodetection of Ki-67 LI and PR expression in meningiomas provides a practical tool for assessing the biological behavior of meningiomas.