Brain tumor
Glioblastoma multiforme (GBM) is the most aggressive (grade IV) and most common form of a malignant brain tumor. Even when aggressive multimodality therapy consisting of radiotherapy, chemotherapy, and surgical excision is used, median survival is only 12–17 months. Standard therapy for glioblastoma multiforme consists of maximal surgical resection of the tumor, followed by radiotherapy between two and four weeks after the surgical procedure to remove the cancer, then by chemotherapy, such as temozolomide. Most patients with glioblastoma take a corticosteroid, typically dexamethasone, during their illness to relieve symptoms. Experimental treatments include targeted therapy, gamma knife radiosurgery, boron neutron capture therapy and gene therapy.
Astrocytoma
For low-grade astrocytomas, removal of the tumor generally allows functional survival for many years. In some reports, the 5-year survival has been over 90% with well-resected tumors. Indeed, broad intervention of low-grade conditions is a contested matter. In particular, pilocytic astrocytomas are commonly indolent bodies that may permit normal neurologic function. However, left unattended, these tumors may eventually undergo neoplastic transformation. To date, complete resection of high-grade astrocytomas is impossible because of the diffuse infiltration of tumor cells into normal parenchyma. Thus, high-grade astrocytomas inevitably recur after initial surgery or therapy, and are usually treated similarly as the initial tumor. Despite decades of therapeutic research, curative intervention is still nonexistent for high-grade astrocytomas; patient care ultimately focuses on palliative management.