Gene Might Predict Brain Tumors' Aggressiveness
Scientists zero in on DNA sequence associated with gliomas
MONDAY, Aug. 27, 2012 (HealthDay News) -- A gene variant that increases the risk of certain types of brain tumors has been identified by U.S. researchers, who say their findings could help identify people at risk of developing these tumors and improve their treatment.
The team found that people who carry a "G" instead of an "A" at a specific location in their genetic code have about a sixfold increased risk of developing certain subtypes of gliomas, which account for about 20 percent of brain cancers diagnosed in the United States.
The study was published online Aug. 26 in the journal Nature Genetics.
The researchers said they still have to confirm whether this location in the genetic code is the source of tumors. Even if it's not, "it is pretty close," study senior author Dr. Robert Jenkins, a pathologist at the Mayo Clinic Cancer Center in Rochester, Minn., said in a Mayo news release.
"Based on our findings, we are already starting to think about clinical tests that can tell patients with abnormal brain scans what kind of tumor they have, just by testing their blood," Jenkins added.
"Being able to tell people that the mass in their brain is this type of tumor is actually good news, because it has a much better prognosis than other brain tumors," he explained. "So what is it that predisposes people to develop less aggressive, but still lethal, gliomas? That makes understanding the function of this variant even more important."
The study was co-authored by Jenkins along with Margaret Wrensch and John Wiencke, professors in the department of neurological surgery at the University of California, San Francisco.
The hunt for regions of the human genome that might be associated with the development of gliomas began a few years ago and led researchers to a portion of chromosome 8 that contained DNA sequence variations (single nucleotide polymorphisms, or SNPs) associated with brain tumors.
In this study, the researchers pinpointed an SNP called rs55705857 and found that the less common "G" version of this SNP was strongly associated with slower growing gliomas.
The U.S. National Cancer Institute has more about brain cancer.