Molecular markers of gliomas: a clinical approach

Over the last decade, the knowledge on the molecular genetic background of gliomas has dramatically increased. This information provides the basis for the molecular target therapies and molecular tests serve to complement the subjective nature of histopathologic criteria and add useful data regarding response to treatments and prognosis. In particular, the use of loss of heterozygosity (LOH) and methylation specific polymerase chain reaction (PCR) (MSP) based testing of gliomas is already in place and used clinically in several centers. This paper provides a brief overview of these molecular genetic aberrations and discusses the clinical utility, as well as the advantages and disadvantages of such approach. Newly developed molecular techniques, such as LOH testing, fluorescence in situ hybridization (FISH), DNA sequencing and MSP, are currently being employed in assessment of gliomas in some laboratories. However, the clinical use of some markers and the context in which the information obtained should be used are still not entirely understood. Therefore, this paper will focus on validation and implementation of molecular testing in gliomas, with emphasis on LOH on chromosomes 1p, 19q, 17p and 10q and O(6)-methylguanine-DNA methyltransferase (MGMT) methylation status.