Postoperative radio-chemotherapy - a new standard in treatment for glioblastoma?

Abstract

A median survival in patients with glioblastoma multiforme after surgical resection and high dose radiation therapy is less than 1 year. Promising prospects in treatment these patients create phase III multicenter trials with concomitant usage of postoperative radiochemotherapy with themozolomid. This is an orally administered alkylating agent, that is able to cross the blood-brain barrier. In this agent case alkylation is the transfer of an alkyl group (in this particular case - methyl group) to the DNA and it usually concern a guanine as a target. The DNA-repair enzyme - O6-methylguanine-DNA methyltransferase (MGMT) removes a methyl group from methylated guanine and that way possibly inhibits the killing of tumor cells by alkylating agents. Methylation of the MGMT’s promoter makes impossible to procced with transcription, and the same inhibits producing of MGMT. It may results in lack of DNA repair which is alkylated by agent and the same may be associated with longer survival in patients with glioblastoma.