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.
IDH1
Mutations in "IDH1" are also implicated in cancer. Originally, mutations in "IDH1" were detected in an integrated genomic analysis of human glioblastoma multiforme. Since then it has become clear that mutations in "IDH1" and its homologue "IDH2" are among the most frequent mutations in diffuse gliomas, including diffuse astrocytoma, anaplastic astrocytoma, oligodendroglioma, anaplastic oligodendroglioma, oligoastrocytoma, anaplastic oligoastrocytoma, and secondary glioblastoma. Mutations in "IDH1" are often the first hit in the development of diffuse gliomas, suggesting "IDH1" mutations as key events in the formation of these brain tumors. Glioblastomas with a wild-type "IDH1" gene have a median overall survival of only 1 year, whereas "IDH1"-mutated glioblastoma patients have a median overall survival of over 2 years.