Removing 'non-contrast enhancing tumor' may boost survival of glioblastoma patients

Survival may more than double for adults with glioblastoma, the most common and deadly type of brain tumor, if neurosurgeons remove the surrounding tissue as aggressively as they remove the cancerous core of the tumor.

This discovery, reported in a retrospective study headed by researchers at UC San Francisco, is welcome news for those in the glioblastoma community, which celebrated its last breakthrough in 2005 with the introduction of the chemotherapy drug temozolomide.

Removing the "non-contrast enhancing tumor" – so called because it does not light up on MRI when a contrast agent is injected into the vein – represents a paradigm shift for neurosurgeons, according to senior author and neurosurgeon Mitchel Berger, MD, director of the UCSF Brain Tumor Center.

Traditionally, the goal of neurosurgeons has been to achieve total resection, the complete removal of contrast-enhancing tumor. This study shows that we have to recalibrate the way we have been doing things and, when safe, include non-contrast-enhancing tumor to achieve maximal resection."

Mitchel Berger, MD, senior author, who is also affiliated with the UCSF Weill Institute for Neurosciences

Some 22,850 Americans are diagnosed each year with glioblastoma – one of the most relentless adult cancers and one that may be best known for claiming the lives of senators John McCain and Edward Kennedy, and the son of Vice President Joe Biden. The average survival for the 91 percent of glioblastoma patients whose tumor is characterized by IDH-wild-type mutations is 1.2 years, according to a 2019 study. However, the remaining 9 percent have a type of glioblastoma classified as IDH mutant, with average survival of 3.6 years.

In their study, which publishes in JAMA Oncology on Feb. 6, 2020, the researchers tracked the outcomes of 761 newly diagnosed patients at UCSF who had been treated from 1997 through 2017. The patients, whose average age was 60, were divided into four groups with varying risk based on age, treatment protocols, and extent of resections of both contrast-enhancing and non-contrast-enhancing tumor.