ABSTRACT
INTRODUCTION WHO grade 3 (anaplastic astrocytoma, anaplastic oligodendroglioma, and anaplastic oligoastrocytoma) and grade 4 gliomas (glioblastoma multiforme and gliosarcoma) are collectively referred to as malignant gliomas. Glioblastoma multiforme (GBM) has an infi ltrative tissue pattern in which a complete surgical resection is not possible. Currently, the standard treatment for GBM is surgical resection followed by a combination of radiotherapy and chemotherapy. Varying modes of chemotherapy have been used for decades in neuro-oncology; however, there is an increasing concern about its limited effi cacy as well as signifi cant side effects noted in clinical trials. Recently, molecularly targeted therapies for malignant gliomas have been investigated in clinical trials, but to date only bevacizumab (Avastin®, Genentech, South San Francisco, CA) has been approved for clinical use by the Food and Drug Administration (FDA) ( 1 ). The median survival of GBM patients is about 15 months despite aggressive conventional therapies ( 2 ). According to data from National Cancer Institute, there were approximately 62,930 newly diagnosed cases of brain tumor, with 13,000 deaths, in the year 2010. Among all the newly diagnosed cases, 22,070 cases will be primary malignant brain tumors, representing 1.5% of all primary malignant cancers expected to be diagnosed annually in the United States ( www.cancer.gov ).
