Brain cancer is many different diseases, all too often with the common denominator of being hard to treat. Just the names are intimidating – glioblastoma, astrocytoma, ependymoma, oligodendroglioma, meningioma – even when the prognoses aren’t (meningiomas may be curable, for example).

For many brain cancers, though, the outlook remains poor despite recent medical advances. They are often incurable, and so the goal of treatment is to extend lives while preserving quality of life. To understand the state of affairs in brain cancer treatment and help answer some common questions about brain cancer, UCHealth Today caught up with Dr. Douglas Ney, a University of Colorado School of Medicine neuro-oncologist who practices at UCHealth University of Colorado Hospital on the Anschutz Medical Campus.

Does a brain tumor mean brain cancer?

No – there are roughly 150 types of brain tumors, many of which are considered benign tumors – including many of the meningiomas mentioned above, which account for 10 to 15% of all brain tumors but a tiny percentage of brain cancers.

What are some symptoms of brain cancer?

They vary but include headaches severe enough to wake up a patient at night, seizures, difficulty communicating, personality changes, disorientation, confusion, partial body weakness or paralysis, changes in vision or hearing, balance difficulties, nausea, and facial numbness or tingling.

How do doctors diagnose brain cancer?

Typically, CT and MRI scans determine the locations and sizes of tumors, and then surgery is needed to characterize the tumor. If it’s cancerous, a pathologist provides a tumor grade and type. Gliomas, the most common malignant brain tumors, are typically graded on a 1-4 scale. Grade 1 brain cancers grow slowly and can be curable with successful surgery to remove the tumor. Grade 4 brain cancers grow quickly, resist treatment, and are typically incurable.

What are some common types of brain cancer?

First, there are two broad categories of brain cancer. The first involves cancers that originate in the brain, called primary brain tumors.

The second category involves cancers that started elsewhere – such as lymphomas, breast cancers, prostate cancers, bone cancers, lung cancers, and others. These are called secondary, or metastatic, brain tumors. Primary brain tumors are the main focus of neuro-oncologists such as Ney, though neuro-oncologists also help patients with metastatic brain tumors by working with the doctors who specialize in those other cancers.

What are the main types of primary brain tumors?

Gliomas are, as mentioned, the most common primary brain cancer, comprising between a quarter and one-third of all brain tumors and about 80% of all malignant brain tumors. These originate in the glial cells that surround and support the brain’s neurons. There are several types of gliomas.

Glioblastomas account for 50% to 60% of gliomas and are the most common primary brain cancer in adults. Gliomas and glioblastomas are incurable. His glioblastoma patients often survive 18-22 months, Ney says. That’s not good, but it’s better than the statistical average of eight months or 14 months, depending on the source.

“There’s a whole group of people who are doing much, much better than that,” Ney says. “We go at it aggressively, we watch it closely, and we treat it with everything in our arsenal.”

Why are brain cancers so hard to treat?

Many brain tumors, gliomas and glioblastomas among them, are not solid masses with clear boundaries, but rather “diffusely infiltrative,” penetrating weblike into the surrounding tissues, Ney says. That makes complete surgical removal impossible, he says.

Also, even single categories of brain cancers – glioblastomas, say – are in fact maddeningly diverse.

“I think of glioblastoma as hundreds of diseases, because they’re so different in a molecular fashion,” Ney says. “There are so many things driving the growth of these tumors, it’s impossible to target them all.”

Another challenge is the blood-brain barrier, which makes it hard to deliver medications directly to the brain.

What are typical brain cancer treatments?

Chemotherapy and radiation have been the mainline treatments, with surgery also an option when doable. Promising drugs are emerging, though. While whole-brain radiation therapy can be done, Ney describes it as “very toxic, and it also actually doesn’t improve tumor control.” Rather, focused radiation is the primary approach.

Studies have not found Gamma Knife, CyberKnife, proton-beam, or other “fancy forms of radiation,” as Ney puts it, to be superior to standard radiation therapy, he says.

For glioblastoma patients, there’s also the option of wearing Novocure’s Optune device, which sends alternating electric fields into to the brain and has been proven to disrupt the proliferation of the brain cancer’s cells. Patients have survived for years thanks to the device. Ney says about 50 UCHealth patients are wearing Optune devices at a given time.

What are promising drugs for brain cancer?

The U.S. Food and Drug Administration in August 2024 added vorasidenib to the list of U.S.-approved brain-cancer drugs. It’s for patients with two common types of gliomas – grade 2 astrocytoma and oligodendroglioma. Most of these tumors contain a genetic mutation called IDH mutations. Vorasidenib targets IDH mutations and inhibits tumor growth.

The study that led to vorasidenib’s approval found that those on the drug had a median progression-free survival of 27.7 months, versus 11.1 months in the control group that didn’t take the drug.

“I think it’s really going to move the needle in terms of outcomes,” Ney says. “It’s not for every patient, but it’s a really good example of the sort of innovation that’s on the horizon, and it’s going to change how we think about the treatment of these tumors.”

Are new brain cancer treatments being developed?

Several lines of early-stage research are afoot. Immunotherapies, in which drugs or genetic manipulation teach the immune system to attack cancer cells that otherwise hide themselves from our immune defenses, are one emphasis. Researchers are studying the use of CAR T-cell therapies for glioblastomas, and the early results look promising. Also, the National Cancer Institute is in the early stages of testing a vaccine that activates immune cells to recognize and attack glioblastoma cells.

Another focus area of brain cancer research is in improving the delivery of drugs to the brain, which the blood-brain barrier hinders. One approach is to use low-intensity ultrasound to disrupt the blood-brain barrier. Another is convection-enhanced delivery, which places catheters to deliver drugs directly to the brain cancers doctors want to target. Researchers are even experimenting with genetically manipulating Toxoplasma gondii parasites to deliver large-molecule drugs straight to neurons.

“I think it’s a pretty exciting time in the brain tumor field right now,” Ney says. I’m super-optimistic about the field.”

What’s behind that optimism? There’s still no cure for brain cancer for so many patients, right?

“We don’t always have the luxury where we can say, ‘Hey, I’ve taken it all out, mission accomplished,’” Ney says. “It doesn’t just become about treating the disease. It becomes about, ‘How do you help a patient have the best quality of life? How do you kind of walk that path with them – to help them understand their disease?’”