The study identifies patients with longer-than-expected survival times. The research used epigenomics to determine that tumor DNA methylation profiles were distinctly different in about ten percent of patients with glioblastoma multiforme (GBM). "Most GBM patients survive fewer than 15 months, and fewer than ten percent live more than five years," said Peter W. Laird who led the research team in collaboration with others. "With this research, we have identified a subset of patients with a distinct type of GBM that have substantially better clinical outcomes, with a median survival time of more than three years from the time of diagnosis."
Epigenomics is the study of how DNA is packaged and marked to control which genes can be used in a particular type of cell or tissue. The distribution of one of these marks along the DNA, called DNA methylation, is often abnormal in cancer, contributing to the disease process.
The characteristic epigenetic profile discovered by the research team is called G-CIMP (Glioma CpG Island Methylator Phenotype) and was found to occur in much younger patients. G-CIMP tumours have other distinct alterations in their genomic landscape, revealing an interesting association with an acquired mutation in the IDH1 gene.
"Such findings are critical to the detection and treatment of brain cancer based on the genetic or epigenetic profile of each patient's disease," said National Institutes of Health (NIH) Director Francis Collins.
MEDICA.de; Source: University of Southern California