Genetic defect is linked to common brain cancers

In a discovery that researchers hope could lead to better treatments for intractable brain tumors, scientists from Johns Hopkins Kimmel Cancer Center and Duke University Medical Center have found a genetic defect in a large number of common brain cancers and believe it could hold clues to why some people with the disease fare better than others.

The findings, published in today's New England Journal of Medicine, could ultimately help determine biologically how deadly a tumor is, providing far more information than what doctors can now learn by examining these cancers under a microscope.


Though preliminary, oncologists were excited about their findings, however incremental, because patients with brain cancer have so few good treatment options available and because survival rates for many forms of the disease remain low.

"The prognosis for many of these tumors is terrible, and the treatments for these tumors are ridiculously poor," said Dr. Will Parsons, visiting professor in pediatric oncology at Hopkins and co-author of the study. "Any way we could improve the care of these patients would make a big difference."


Parsons, an assistant professor at Baylor College of Medicine, and his colleagues at Hopkins and Duke do not know what role the gene mutations they have identified - known as IDH1 and IDH2 - play in the formation and growth of tumors. "You need to know that to figure out how to target it," he said.

But the researchers do know that patients with these gene-altered tumors appear to survive at least twice as long as those without them, and that information could help doctors determine what existing treatments to use on a given patient.

Dr. Mark Gilbert, a neuro-oncologist at the University of Texas M.D. Anderson Cancer Center who was not involved in the research, said that a few of the patients he treated nearly two decades ago are still alive, while some don't make it through a first round of treatment. Knowing in advance, he said, could save time and save lives.

"There are some people whose tumors don't respond to standard therapies, and if we knew that in advance we would try something different," he said. "We have all to gain and nothing to lose."