A narrative review of targeted therapies in meningioma

Meningiomas are the most common primary brain tumors constituting approximately one third of all primary brain tumors. It affects mainly elderly population with increased incidence older than 65 years of age and more woman than man. It usually follows a benign course with a fairly good outcome and the surgery and or radiation therapy remain the standard of care. The prognosis remains excellent for grade I meningiomas with 10-year overall survival greater than 90%. However, although the most of the meningiomas, especially for grade I, can be cured by surgery alone, for grades II and III recurrent meningiomas, they become a clinical challenge as there are no clear standard treatment options available after re-resection or re-irradiation therapy. Prognosis is particularly poor for grade III meningiomas with 10- year overall survival of 33%. Many chemotherapeutic agents and hormonal therapies have been tried with only modest benefits. Recent advances in molecular genetic profiling and diagnostic tools greatly enhanced our understanding of the complex pathways and it opened an opportunity for potential targeted therapies for specific markers. Clinical trial results from sunitinib [multitargeted tyrosine kinase inhibitor (TKI)], bevacizumab (VEGF inhibitor), everolimus (mTOR inhibitor) and bevacizumab revealed some promising tumor response in recurrent meningiomas. Currently, many clinical trials including targeted therapies, antiangiogenic agents and immunotherapies are being investigated or under consideration.