Opportunities for clinical research in meningioma.

Meningiomas, when benign, are commonly treated with surgical resection alone. However, the optimal treatment for patients with subtotally resected or recurrent World Health Organization (WHO) grade I tumors, or WHO grade II and III tumors, regardless of the extent of resection, is not well defined, with both a paucity of high quality published evidence as well as a perceived minimal clinical effect for currently available interventions, specifically in terms of prolonging survival. In consideration of the size of the patient population with incompletely treated or non-benign meningiomas, there are opportunities for conducting high quality, prospective, multicenter clinical trials. In this review, we discuss a number of trials that were attempted and/or completed by cooperative groups or clinical consortia, and describe areas of clearly unmet need in terms of defining the optimal treatment regimens. Finally, we discuss ongoing efforts to develop new trials to more definitively address important therapeutic questions.