Glioblastoma Multiforme: A Review of its Epidemiology and Pathogenesis through Clinical Presentation and Treatment

Abstract

Glioblastoma multiforme (GBM) is one of the most malignant types of central nervous system tumors. Despite advances in treatment modalities it remains largely incurable. The objective of our review is to provide a holistic picture of GBM epidemiology, etiology, pathogenesis, clinical findings and treatment. A literature search was conducted for GBM at PubMed and Google Scholar, with relevant key words like glioblastoma multiforme, pathogenesis, signs and symptoms, treatment etc., and papers published until 2015 were reviewed. It was found that radiation and certain genetic syndromes are the only risk factors identified to date for GBM. Depending on the tumor site patients may present to the clinic with varying symptoms. To confirm the presence and the extent of tumor, various invasive and non-invasive imaging techniques require employment. The literature survey revealed the pathogenesis to involve aberrations of multiple signaling pathways through multiple genetic mutations and altered gene expression. Although several treatment options are available, including surgery, along with adjuvant chemo- and radio-therapy, the disease has a poor prognosis and patients generally succumb within 14 months of diagnosis.

Keywords: Glioblastoma multiforme; epidemiology; MRI scan; mutations; temozolomide.

Figure 1

Genetic and Molecular Pathogenesis of GBM. (A) Aberrations involved in primary and secondary GBMs (B) Subtypes of primary and secondary GBMs. (Adapted from Agnihotri et al., 2013)

Figure 2

Four Different Patients with GBM that Illustrate the Heterogeneity in the Anatomic Lesion. The contrast-enhanced axial T1-weighted (TR, 600 msec; TE, 14 msec) images demonstrate variegated appearance of GBM: (a) rim-enhancing mass with central necrosis in the right parietal lobe with surrounding edema; (b) irregularly enhancing mass that crosses the corpus callosum; (c) well-circumscribed homogeneously enhancing mass in the left frontal lobe with no associated edema; (d) ill-defined infiltrative mass in the left medial frontal lobe with no appreciable necrosis. (Adapted from: Nelson and Cha, 2003).