Donald O'Rourke, MD, Associate Professor of Neurosurgery at the University of Pennsylvania School of Medicine and colleagues, were able to accurately predict the specific genetic mutation that caused brain cancer in a group of patients studied using magnetic resonance imaging (MRI).
The researchers presented their findings this week at the American Association for Cancer Research 100th Annual Meeting 2009.
"The field of cancer research has evolved to the point where the identification of the mutations that cause tumors has changed how we treat patients in a number of cancers," says O'Rourke. "Potentially, we believe we have a method that uses MRI to identify a tumor mutation. Historically tumor mutations have been identified in only one way: take the tissue out and examine it using one of two laboratory tests to see if the mutation is present. In this study we've done this identification noninvasively. To my knowledge this is the first demonstration that an MRI, or any imaging technique, can accurately predict the type of mutation of a human tumor."
A particular MRI technique, called relative cerebral blood volume that measures blood flow to the tumor, very highly correlates with the presence of an important mutation in glioblastoma, a type of brain cancer. The mutation occurs in the epidermal growth factor receptor, EGFR, a well known cancer-related protein that helps tumors form their necessary blood vessels. EGFRvIII, the specific mutation the Penn group studied, is the hallmark of a more aggressive form of glioblastoma.
The research team compared MRI readings to tumor tissue samples from 97 glioblastoma patients. They found that patients with higher relative cerebral blood volume as measured by MRI correlates with the EGFRvIII mutation compared to those who did not have the mutation.
Glioblastoma is a variable disease, and clinicians need help to distinguish one form from another. "All of cancer research is evolving to a point where mutations can facilitate care, so a more accurate diagnosis and treatment course can be better planned by identifying the mutational status of the tumor," says O'Rourke.