Impacts of Biology in Therapeutic Management of Malignant Gliomas

Abstract

Primary malignant brain tumours are one of the most aggressive forms of human cancer. Gliomas constitute the predominant brain tumours and the current review focuses on the biology and current management of the same. Gliomas can occur anywhere in the neuroaxis across all age groups and usually present with symptoms related to mass effects. Magnetic resonance imaging (contrast enhanced) with newer techniques of MRS and MR perfusion giving several additional information, is the current
standard diagnostic imaging modality for presumptive diagnosis of brain tumour and histological evaluation is the gold standard for confirmation and further characterisation. Gliomas are heterogenous group of tumours with varied histological types, different grades and varying biology with molecular mechanisms. For the broader purposes, the gliomas are divided into low and high grades. Presently the accepted molecular markers for prognostication and other management purposes are 1p19q
deletion, IDH mutation and O6-methylguanine methyltransferase (MGMT) promoter methylation. Currently, surgery remains the standard first line of management in surgical amenable cases and addition of radiation and chemotherapy in cases of high grade tumours. Chemotherapeutic options in cases of brain tumours are essentially limited due to inability to achieve therapeutic concentration caused by blood brain barrier. There has been
a tremendous insights in understanding the molecular biology of these tumours and several targeted therapeutic options have been identified. Some of them are already in clinical trials and next decade or so is likely to crystallize the routine use of some of them in the clinics.