‘Freaks and Geeks’ Star Busy Philipps, 47, Discovered Rare, Slow-Growing Brain Tumor After Prenuvo Scan—What to Know About Gliomas

Phillips—who was diagnosed with a grade 2 oligodendroglioma [tumor that develops in the oligodendrocytes, which assist in nerve cell function] despite having no symptoms—ultimately underwent surgery this past spring, after learning she had the brain tumor in February, she exclusively told People.

RELATED: What I Learned From My Full-Body MRI Scan by Prenuvo: SurvivorNet Writer Danielle Cinone Shares Her Story—Never Skip Approved Screenings

In the recent conversation, the actress—who lives in New York City—shared that surgeons removed her tumor just weeks before production began on the new CBS legal drama “Cupertino,” where she’s playing Natalia Boutella.

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Philipps explained that her decision to get scanned wasn’t driven by any particular symptom or concern—it was more of a gut instinct. She’d actually raised the idea with her primary care doctor back in 2025, but was told the scan wasn’t necessary at the time.

However, her mind changed after a conversation with an internist in Beverly Hills, who encouraged her that having more information is always better than less, prompting her to schedule the scan.

After receiving her results, Philipps spoke with a neurologist at NYU Langone who treats her daughter’s epilepsy. Reviewing the MRI, he identified a lesion and, based on its shape, told her that the likelihood of it being a glioblastoma—an aggressive form of brain cancer—was low. Still, he recommended an immediate follow-up MRI to determine exactly what it was.

A Patient’s Perspective: Talking To Your Kids About Your Diagnosis

After the MRI confirmed the type of brain tumor, Philipps underwent a five-hour surgery in March to remove and biopsy the mass, which measured 2.6 cm.

According to the American Brain Tumor Association, oligodendrogliomas are an uncommon type of brain tumor, representing about 1.3% of brain tumor cases nationally, with an estimated 1,100 new cases diagnosed annually in the U.S. Additionally, adults are the primary population affected, with onset most typical between 20 and 40 years old. Both sexes can develop these tumors, though men are diagnosed somewhat more frequently than women. Diagnosis in children younger than 15 is uncommon.

Philipps’s neuro-oncologist, Dr. Alexandra Miller, Director of the Neuro-Oncology Division at NYU Langone Health, told People, “It is considered malignant, but it has the best prognosis of all of the malignant gliomas.”

Dr. Miller previously told SurvivorNet, “Glioma is a broad term that refers to a whole range of different types of primary brain tumors. So, they’re tumors that originate in the brain and very rarely spread outside the brain to other parts of the body.”

Diagnosing Gliomas — Dr. Miller Talks About Resections & The Grading System

About a month after the successful surgery, she developed an infection in her surgical incision and needed another operation—this time to treat the infection and remove one of the titanium tacks that had been used to hold her skull bone in place during the first procedure.

Philipps, who is doing well, now hopes sharing her experience will encourage others to take their health seriously and avoid putting off medical care.

“We are frequently told by doctors that there is nothing to worry about [when] you kind of know that there’s something to worry about. There’s nothing to be afraid of in having information. It’s only empowering,” she explained.

Philips concluded, “This time in my life has been so weird. Weird and wonderful kind of in a way. Really enlightening and kind of magical.

“The confluence of circumstances and the timing of everything lining up the way that it did in order for everything else to line up the way that it did. I’m incredibly grateful.”

Philipps is grateful that surgery successfully removed the cancerous tumor, meaning she does not need chemotherapy or radiation. However, she will require regular scans to monitor for any signs of recurrence.

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For patients diagnosed with oligodendrogliomas, surgery is often the first step in treatment.

Treatment may include:

• Surgery:The goal is to remove as much of the tumor as safely as possible without damaging surrounding brain tissues. It’s a specialized procedure performed by expert neurosurgeons.
• Radiation Therapy: This method uses high-energy beams, like X-rays, to kill the tumor cells. It’s often used after surgery, especially if the entire tumor cannot be removed.
• Chemotherapy: Chemotherapy uses drugs to kill the tumorous cells. It might be used after radiation therapy or in combination with it, depending on the specifics of your case.
• Targeted Therapy: This type of treatment focuses on specific abnormalities present in the cancer cells. By blocking these abnormalities, targeted therapy drugs can cause cancer cells to die. This is usually used if the tumor returns after initial treatment.
• Supportive (Palliative) Care: This isn’t a treatment for the tumor itself, but an essential part of any cancer care. Palliative care focuses on providing relief from symptoms and improving your quality of life, through physical therapies, relaxation techniques, and emotional and psychological support.

Philipp’s story reminds us about how important it is to be proactive when it comes to your health.

“If I had any advice for you following a cancer diagnosis, it would be, first, to seek out multiple opinions as to the best care,” National Cancer Institute Chief of Surgery Steven Rosenberg told us in a previous interview, “because finding a doctor who is up to the latest of information is important.”

RELATED: Second (& Third) Opinions Matter When Deciding Between Surgery or Radiation

As we highlight in several areas of SurvivorNet, highly respected doctors sometimes disagree on the right course of treatment, and advances in genetics and immunotherapy are creating new options. Also, in some instances the specific course of treatment is not clear cut. That’s even more reason why understanding the potential approaches to your disease is crucial.

At the National Cancer Institute, there is a patient referral service that will “guide patients to the right group depending on their disease state so that they can gain access to these new experimental treatments,” Rosenberg says.

Cancer Research Legend Urges Patients to Get Multiple Opinions

Furthermore, getting another opinion may also help you avoid doctor biases. For example, some surgeons own radiation treatment centers. “So there may be a conflict of interest if you present to a surgeon that is recommending radiation because there is some ownership of that type of facility,” Dr. Jim Hu, director of robotic surgery at Weill Cornell Medical Center, tells SurvivorNet.

Other reasons to get a second opinion include:

• To see a doctor who has more experience treating your type of cancer
• You have a rare type of cancer
• There are several ways to treat your cancer
• You feel like your doctor isn’t listening to you, or isn’t giving you good advice
• You have trouble understanding your doctor
• You don’t like the treatment your doctor is recommending, or you’re worried about its possible side effects
• Your insurance company wants you to get another medical opinion
• Your cancer isn’t improving on your current treatment

Bottom line, being proactive about your health could be a matter of life or death. Learn as much as you can from as many experts as you can, so that you know that you did your best to take control of your health.

Making Sense of a Brain Tumor Diagnosis

According to the American Society of Clinical Oncology (ASCO), brain tumors account for 85-90% of all primary central nervous system (CNS) tumors. They can either be cancerous (malignant) or non-cancerous (benign), and depending on where the tumor forms in the brain, doctors determine its type, potential symptoms, and potential treatment.

WATCH: Debunking 5G Claims Causing Brain Cancer

Signs and Symptoms of Brain Tumors

Brain tumors impact a person’s brain function and overall health, depending on their size, type, and location within the brain. Tumors that grow big enough and disrupt normal central nervous system functioning can press on nearby nerves, blood vessels, or other tissues. The disrupted central nervous system can present in various ways, making walking or maintaining balance difficult.

However, it’s important to know that brain tumors do not always cause symptoms.

Other signs of brain tumors may include:

• Headaches
• Difficulty speaking or thinking
• Weakness
• Behavioral changes
• Vision changes
• Seizures
• Loss of hearing
• Confusion
• Memory loss

Types of Cancerous and Non-Cancerous Brain Tumors

A brain tumor can affect you differently depending on its location and if it is cancerous. Some brain tumors are non-cancerous (or benign). According to the National Cancer Institute, some examples of these types of brain tumors include:

• Chordomas are primarily benign and slow-growing and are often found near the tailbone or where the spine meets the skull.
• Craniopharyngiomas are rare, slow-growing tumors that don’t spread to other parts of the brain or body. They form near the pituitary gland, near the base of the brain.
• Gangliocytomas are rare tumors of the central nervous system that tend to form on the temporal lobe (the left or right side of the brain).
• Glomus jugulare is a rare and slow-growing tumor.
• Meningiomas are rare brain tumors that usually form on the outer layer of tissue that covers the brain (dura mater).
• Pineocytomas are rare and slow-growing tumors located in the pineal gland near the middle of the brain.
• Pituitary adenomas are slow-growing brain tumors of the anterior pituitary located in the lower part of the brain.
• Schwannomas are rare tumors that grow on the cells that protect nerve cells. They are called Schwann cells.
• Acoustic neuromas (vestibular schwannoma) are slow-growing tumors that develop from the nerves that help balance and hearing.

Other brain tumors are malignant or cancerous. These kinds of tumors include:

• Gliomas are the most common form of cancerous and aggressive primary brain tumors.
• Astrocytoma (glioma) forms in astrocytes (star-shaped cells). Depending on how aggressive or fast they grow and impact brain tissue, these tumors are classified into four grades.
• Ependymomas are tumors classified into three grades depending on how aggressive or fast they grow.
• Oligodendroglioma tumors are classified into grades depending on their growth speed. Grade 2 oligodendroglioma tumors [the type Philips was diagnosed with] are slow-growing and can invade nearby tissue, but they may not present symptoms for many years before detection. Meanwhile, grade 3 oligodendroglioma tumors proliferate.
• Medulloblastoma tumors are classified into four different grades depending on their aggressive nature or how quickly they grow.
• Glioblastoma, which is considered a central nervous system (CNS) tumor, is the most common and aggressive brain tumor in adults.

WATCH: Liquid Biopsy: What It Is And Why You Might Need One As a Cancer Patient

Inside Brain Tumor Surgery and Recovery: What Patients Can Expect

Surgery to remove a brain tumor is delicate by nature, and every movement inside the skull must balance precision with safety.

“We take off the bone overlaying the area we need to get to. We open the little envelope around the brain called the dura, and then we move through the brain tissue to get to where the tumor is to try to cut out as much as we can safely—without hurting the patient’s function or other important things like big blood vessels that can cause things like a stroke,” board-certified neurosurgeon at Emory University School of Medicine Dr. Kimberly Hoang tells SurvivorNet.

Following surgery, patients are closely monitored and often receive radiation to prevent tumor regrowth—particularly in cases where multiple tumors or metastatic disease are involved.

“Because many patients can have more than one brain tumor or metastasis from their cancer, it was not reasonable to think about surgery for them,” Dr. Hoang adds. “They also get radiation for those spots as well, to try to keep those tumors from growing or shrink them down.”

Treatment Advancements & the Challenge of the Blood-Brain Barrier

Chemotherapy, immunotherapy, and targeted therapies have long been effective in treating cancer throughout the body. But the brain’s natural defense — the blood-brain barrier — makes these treatments less effective when it comes to brain tumors.

This barrier is “a network of blood vessels and tissue…made up of closely spaced cells and helps keep harmful substances from reaching the brain,” according to the National Cancer Institute.

Still, Dr. Hoang notes that recent advancements in drug design are beginning to improve treatment efficacy in the brain.

Understanding Side Effects of Brain Tumor Treatment

Side effects vary depending on the tumor’s size, location, and number of lesions present.

“Radiation treatment can cause swelling in the tumor as the tumor ‘dies,’ and the surrounding tissue can also become swollen as the treatment takes effect,” Dr. Krishanthan Vigneswaran, a neurosurgeon with UT Health Houston and Memorial Hermann, tells SurvivorNet.

“This swelling can cause symptoms of headache, nausea, vomiting, and neurological loss of function…Surgical resection can also induce swelling, but this is more transient.”

Tumor location often determines what symptoms emerge:

“If it’s near your movement area, movement on one side of the body can be affected. If it’s near your speech area, your speech and the way you form words and express them can be affected,” Dr. Hoang explains.

She also notes brain surgery tends to be less painful than other types — like spinal or abdominal — due to fewer nerves in the surgical area.

Recovery & Long-Term Monitoring

Simpson still receives recurring MRI scans to monitor his brain for any signs of cancer progression.
“Because of this unique quality of metastatic brain disease, an oncology team will have to monitor a patient indefinitely during remission,” Dr. Vigneswaran says.

Many experts recommend joining a support group — especially one with people who’ve undergone similar procedures. Their lived experience can offer comfort and practical advice.

“Support groups can be incredibly helpful to patients and are commonly offered at major cancer centers and hospitals,” says Dr. Jennifer Moliterno, Chief of Neurosurgical Oncology at Yale Cancer Center.

Mental health professionals are also often part of the care team, helping patients manage the emotional effects of surgery, treatment, and recovery.

How Genetic Testing Can Make a Difference In Your Glioma Treatment Journey

Gliomas are a type of tumor that starts in the brain. They can range from slow-growing (low-grade) to more aggressive forms.

“Nowadays, with not only brain cancers, but cancers in general, there has been a lot that’s been discovered about how different mutations in the tumor actually affect the behavior. Also, there are a number of mutations for which we have drugs that can target those mutations,” Dr. David Peereboom, an oncologist at the Cleveland Clinic Cancer Center in Ohio, tells SurvivorNet.

Biomarkers are essentially a tumor’s “fingerprints.” By studying these fingerprints, doctors can predict what treatments may be most effective and least toxic for you.

“The way to discover that [biomarker] is to do testing,” Dr. Peereboom explains. “The most helpful testing is called Next Generation Sequencing. What that does is it looks at all the DNA in the tumor, and the DNA is analyzed, and there are parts of DNA that may be abnormal or mutated.”

This testing might be performed using tissue obtained during a biopsy, surgery, or a blood test.

“There are a handful of those mutations that are called driver mutations,” Dr. Peereboom adds. “Driver mutations, as the name implies, are mutations that actually drive the behavior of the cancer. And for a handful of those, they’re actually, nowadays, there are some drugs that will target those mutations.”

How is Molecular Testing Done?

Molecular testing is typically performed on a sample of tumor tissue. This tissue is obtained from either surgery or a biopsy. Pathologists conduct the testing; these doctors are specially trained to study the characteristics of tumor tissues.

Molecular testing is widely available throughout the country, making it accessible to most patients diagnosed with gliomas.

What Types of Molecular Testing Are There?

Several molecular testing techniques are used on tissue samples. One method is antibody staining, where pathologists “stain the tumor with an antibody to look for the presence of the IDH mutant protein,” Dr. Alexandra Miller, Director of the Neuro-Oncology Division at NYU Langone Health, explains. Tumors without the mutation will not be visible with the stain. However, tumors that have the IDH mutation will stain or show a color that pathologists can recognize. This is a very common technique pathologists use for many tumor types.

WATCH: Understanding Molecular Testing for Glioma

Another method is molecular sequencing, which Dr. Miller explains is a process where doctors examine the DNA of the tumor cells to find specific changes or mutations in the genes. Both techniques can confirm whether the IDH mutation is present in the tumor cells.

Dr. Miller tells SurvivorNet that molecular testing “should be performed on every glioma.”

By determining whether a tumor carries the IDH mutation, doctors can offer FDA-approved targeted therapies like Vorasidenib, which Dr. Miller calls a “huge breakthrough” that slows the progression of the disease. This personalized approach marks an exciting advancement in the fight against gliomas, giving patients new hope and better treatment options.

WATCH: Who Benefits From Vorasidenib?

The FDA-approved drug Vorasidenib marks a major advance for patients with IDH-mutant gliomas—especially grade 2 tumors. In the INDIGO trial, a Phase 3 clinical trial, it reduced the risk of disease progression or death by 61% and extended progression-free survival (period with stable disease) from 11.1 to 27.7 months. For many patients, that represents a life-changing difference.

Questions to Ask Your Doctor

If you or a loved one has been diagnosed with a glioma, be sure to discuss molecular testing with your treating team. Here are some questions to ask:

• Do you need both the tissue sample and blood samples for molecular testing?
• What specific mutations will you be testing for in my tumor?
• Do I have any genetic mutation that would change the course of my treatment?
• Am I eligible to receive targeted therapy? What about immunotherapy?
• Is there a clinical trial that would be relevant for me?

Contributing: SurvivorNet Staff

Learn more about SurvivorNet's rigorous medical review process.

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