Glioblastoma muliforme (GBM) is the most common primary brain tumor in adults, with an annual incidence of 3.0–3.6 per 100,000. GMBs fall into the category of grade IV astrocytomas, arising from mutated glial or neural stem cells. GBMs are particularly invasive, aggressive, and almost universally fatal. Individuals diagnosed with GBMs have a median survival rate of less than one year, and fewer than 20 percent survive two years. Despite significant advances in technology and the understanding of tumor pathogenesis, the median overall survival of patients has increased only 3.3 months over the past 25 years.

Facts About GMBs

  • may have evolved from a low-grade astrocytoma or an oligodendroglioma
  • accounts for 17% of all primary brain tumors
  • more common in men than women
  • most common in adults 50-70 years old
  • negative prognosis factors include increased age, biopsy rather than resection, bilateral tumor involvement, poor neurological function, and radiation therapy alone rather than radiation and chemotherapy.
  • overall survival was 9.9 months according to recent study, studying 516 patients


  • often asymptomatic until the tumor gets large; also depends on where the tumor is located, as to what symptoms will occur
  • seizure
  • nausea
  • vomiting
  • headache
  • hemiparesis (weakness on one side of the body)
  • memory or personality changes

Learn about brain anatomy here.

Learn more about brain tumors in this video: Mayo Clinic’s Brain Tumor Diagnosis and Treatment

Dreyfuss, J. M., Johnson, M. D., & Park, P. J. (2009). Meta-analysis of glioblastoma multiforme versus anaplasticastrocytoma identifies robust gene markers. Molecular Cancer, 871-80.

Helseth, R. R., Helseth, E. E., Johannesen, T. B., Langberg, C. W., Lote, K. K., Ronning, P. P., & Meling, T. R. (2010). Overall survival, prognostic factors, and repeated surgery in a consecutive series of 516 patients with glioblastoma multiforme. Acta Neurologica Scandinavica, 122(3), 159-167. doi:10.1111/j.1600-0404.2010.01350.x

National Brain Tumor Association. (2011). Glioblastoma multiforme (GBM). Retrieved March 31, 2012 from

Park, J. K., Hodges, T., Arko, L., Shen, M., Dello Iacono, D., McNabb, A., Olsen Bailey, N., Nguyen Kreisl, T., Iwamoto, F. M., Sul, J., Auh, S., Park, G. E., Fine, H. A., and McL. Black, P. (2010). Scale to predict survival after surgery for recurrent glioblastoma multiforme. Journal of Clinical Oncology, 28(24), 3838-3843.