What is glioblastoma multiforme?
Glioblastoma Multiforme (GBM) is a fast-growing type of malignant brain tumor that is the most common brain tumor in adults. In 2010, more than 22,000 Americans were estimated to have been diagnosed and 13,140 were estimated to have died from brain and other nervous system cancers.1 GBM accounts for about 15 percent of all brain tumors and occurs in adults between the ages of 45 to 70 years.2 Patients with GBM have a poor prognosis and usually survive less than 15 months following diagnosis. Currently there are no effective long-term treatments for this disease. View additional information on brain tumors.
What have The Cancer Genome Atlas (TCGA) researchers learned about GBM?
Over the course of six years of study and two journal publications, TCGA researchers have:
- Established a new subtype of GBM that affects younger adults and has an increased survival rate. A subset of GBM tumors had specific chemical changes called methylation of a large group of genes, which may account for the improved survival of these patients compared to patients with other subtypes of GBM.
- Recognized four distinct molecular subtypes of GBM that respond differently to aggressive therapies. Patients with one subtype survive about 50 percent longer than those with other GBM subtypes. Knowing a tumor’s subtype could help match each patient to the most effective therapies. See more information about TCGA brain tumor subtype studies.
- Identified possible mechanisms involving gene mutations that can cause some GBM tumors to become resistant to therapy after treatment with a standard chemotherapy called temozolomide. This finding could be used to develop new drugs that will not activate this drug resistance mechanism.
- Described new processes that modify the structure of the EGFR gene as well as a region on a chromosome containing the MDM2 and CDK4 genes, which may be important to the development of GBM.
- Pinpointed five gene mutations in GBM tumors that may provide new insights into the biology of this disease:
- ERBB2, a gene involved in breast cancer
- TP53, a gene involved in many types of cancers
- PIK3R1, a gene that controls an enzyme that is found in many cancers
- TERT, a gene that encodes for an enzyme that maintains the protective structures, known as telomeres, covering the ends of chromosomes
- Defined a pattern of mutations involving four genes that regulate chromatin modification. Chromatin is a combination of DNA and protein that packages DNA into chromosomes and controls how genes are expressed. Chromatin modification has previously been associated with ovarian and kidney cancers, and this finding suggests its potential role in GBM cancer as well.
See more about TCGA's study of brain tumors published in 2008 in the journal Nature as well as from 2013 published in the journal Cell.
Where can I find more information about the TCGA Research Network's studies, or studies using TCGA data?
View a list of TCGA scientific publications.
Where can I find clinical trials to treat brain cancer that are supported by the National Cancer Institute (NCI)?
View a list of NCI-supported adult GBM clinical trials that are now accepting patients.
1 American Cancer Society: Cancer Facts and Figures 2010. Atlanta, GA: American Cancer Society, 2010.
2 Levin VA, Leibel SA, Gutin PH: Neoplasms of the central nervous system. In: DeVita VT Jr, Hellman S, Rosenberg SA, eds.: Cancer: Principles and Practice of Oncology. 6th ed. Philadelphia, Pa: Lippincott Williams & Wilkins, 2001, pp 2100-60.