Molecular profiling may improve meningioma decision making

Researchers have demonstrated how molecular profiling of tumors can be used to help predict treatment response and survival in patients with meningiomas, the most common type of primary brain tumor, according to a recent study published in Natural medicine.

The findings underscore the potential of using molecular data to improve clinical decision-making and outcomes for patients with meningiomas, according to Craig Horbinski, MD, PhD, director of neuropathology in the Department of Pathology and co-author of the study.

Meningiomas are tumors that develop from the membranes, or meninges, surrounding the brain and spinal cord. Unlike other types of brain tumors, such as glioblastoma, meningiomas are primarily located outside the brain and rarely spread throughout the brain. They are also unlikely to metastasize to other parts of the body.

First-line treatment is usually surgical resection of the entire tumor. However, many of these tumors recur and require follow-up resection and subsequent radiation therapy, but these treatments are not always effective. If the tumor continues to grow, it can lead to brain damage and long-term cognitive impairment, or even death.

It is only in the last decade, however, that greater attention has been paid to improving treatment strategies for patients with meningiomas, the management of which has not changed significantly in the past 50 years, according to Horbinski.

“Most of the biomedical research efforts have been directed toward other types of brain tumors, particularly gliomas such as glioblastoma. Over the last decade, there has been a growing awareness that we need to do more for patients with these tumors,” said Horbinski, who is also a professor of pathology in the division of experimental pathology and neurological surgery.

In the current study, Horbinski and colleagues sought to better understand the molecular biology of meningiomas and define molecular biomarkers of treatment response by analyzing retrospective data on more than 2,800 meningiomas collected during a previous prospective phase II clinical trial.

The scientists used propensity score matching, a statistical technique, to characterize the benefits of different degrees of tumor resection, in addition to identifying a group of molecularly defined radiation-resistant meningiomas.

From this analysis, the authors found that total tumor resection was associated with longer progression-free survival in all molecular groups and longer overall survival in proliferative meningiomas. Dural margin treatment, in which the tumor membrane is surgically resected in addition to the tumor itself, prolonged progression-free survival compared with no treatment.

“This shows that it’s not enough to remove the entire tumor with the naked eye. We need to do something about the tumor cells that we know are still there, but we can’t see,” Horbinski said.

The scientists also found that tumors that have lost large sections of DNA and changes in how the tumor genome is chemically modified by DNA methylation ultimately determine how the tumor behaves, the researchers found.

“Those two parameters have a lot to say about how these tumors are going to behave, particularly how quickly they’re going to grow back and how they’re going to respond to radiation, if they respond to radiation at all,” Horbinski said.

These findings underscore the clinical utility of molecular tumor testing to predict treatment response in patients with meningiomas and other types of brain tumors, Horbinski said.

“One of the problems we have in pathology and oncology in general is that many third-party payers are reluctant to cover molecular testing because they still view it as experimental. They still view it as not providing meaningful data for patient care and studies like this should really put an end to that idea,” Horbinski said.