Study Links Rare Genetic Marker to Brain Cancer
August 10, 2012 | Dagny Stuart
Glioma is the most common and lethal type of brain tumor, and now investigators from Vanderbilt-Ingram Cancer Center and three other cancer centers have identified a link between a rare genetic variant and the risk of developing glioma. The variant also appears to improve the odds of survival among glioma patients.
Reid Thompson, M.D., William F. Meacham Professor and Chair of the Department of Neurological Surgery, was one of the co-authors of the paper that was published online recently in the Journal of Medical Genetics.
The study — one of the largest epidemiology studies ever done for glioma — was led by Thompson’s former Vanderbilt colleague Kathleen Egan, Sc.D., interim program leader of Cancer Epidemiology and vice chair of the Department of Cancer Epidemiology, Moffitt Cancer Center, Tampa.
The researchers studied patients age 18 and older who had recently been diagnosed with glioma.
The investigators genotyped 566 glioma patients and 603 control subjects, looking for a rare single nucleotide polymorphism (SNP or “snip”) known as rs78378222 in TP53, a tumor suppressor gene.
The SNP interferes with the TP53 signal and has been linked to several forms of cancer.
The researchers found that participants who carried the rare SNP variant were 3.5 times more likely to develop glioma.
However, when the investigators examined the variant’s role in patient survival they found a 50 percent reduction in death rates for carriers of the variant.
The study was the first to confirm a rare susceptibility variant in glioma cases.
“We were surprised by the survival findings linked to this rare variant,” said Thompson, director of the Vanderbilt Brain Tumor Center and of Neurosurgical Oncology. “It isn’t yet clear how or why this genetic variant affects the aggressiveness of this form of brain tumor.”
The authors noted that their study results “may shed light on the etiology and progression of these tumors,” and may aid in identifying individuals who are at risk for glioma.
Other investigators who participated in the study and co-authored the paper include Alvaro Monteiro, Ph.D., James Browning, MPH, and Melissa Madden, MPH, Moffitt; L. Burton Nabors, M.D., University of Alabama at Birmingham; and Jeffrey Olson, M.D., Emory School of Medicine, Atlanta.
Financial support for the research was provided by the National Cancer Institute of the National Institutes of Health under Public Health Service Grant R01CA116174, along with institutional funding from Moffitt and VICC.