Purpose: Meningiomas are the most common benign intracranial tumor, accounting for 30% of all primary intracranial tumors. Although benign meningiomas rarely recur after a complete resection, anaplastic tumors are associated with high recurrence rate and unfavorable outcome. In the current study, we investigated the expression of the multidrug resistance protein 5 (MRP5) in patients with meningiomas.
Methods: We retrospectively studied twenty patients with meningiomas that were treated surgically in our institute over a 3-year period. MRP5 protein expression was determined immunohistochemically.
Results: The immunohistochemical expression of MRP5 was observed only in anaplastic meningiomas. No MRP5 expression was detected in benign or atypical meningiomas. No significant correlation was found between MRP5 expression and Ki-67 index. After a mean follow-up period of 23 months, there were 4 cases of tumor recurrence. No correlation was found between extent of resection and tumor recurrence.
Conclusion: Immunohistochemical MRP5 protein expression was observed only in anaplastic meningiomas. Further research is needed to clarify whether MRP5 is indicative of malignant pathological features in meningiomas and whether possible therapeutic implications exist.