Glioblastoma and the FRONTIER Trial

By: David Grew MD MPH

"Finally, a newer innovative treatment called Tumor-Treating Fields, or TTF, uses a device attached to the scalp to disrupt cell division and extend the time until GBM grows back."

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Glioblastoma, known as GBM for short, is an awful disease for which there are no known silver bullet treatments.  It is the most common high grade (meaning aggressive) primary tumor of the brain.  Primary brain tumors start in the brain and grow within it.  They typically do not spread or metastasize to other parts of the body.  Most patients and families recognize the name glioblastoma and know it's a bad tumor.  And so picking up on the finer details of the workup and treatment roadmap is tough when your head is spinning from news of the terrible diagnosis.  To help them keep two feet on the ground, I’m laying out a simple framework for understanding the contours of GBM diagnosis, workup, treatment and follow up.

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Symptoms:  Symptoms can vary widely depending on the part of the brain the GBM is located.  Some patients have “generalized symptoms” like headache, nausea or vomiting.  These don’t necessarily correspond to the part of the brain the GBM is located. These symptoms happen because there is a lot of swelling in the brain.  Sometimes patients are diagnosed after having a seizure, which prompts scans of the brain.  Other “focal symptoms” can give away the location of the GBM like changes in behavior, weakness on only one side of the body, speech or vision changes.

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Workup:  Any workup for new symptoms includes a good history and physical exam.  Doctors will want to know the timeline, frequency, intensity, and velocity of onset of any new symptoms.  They will also ask about other medical history since GBM can mimic other diseases, like stroke or metastatic cancer.  Ultimately doctors will order scans of the brain - first a CT scan, which is like a 3D x-ray of the brain. Next, they will order an MRI, which gives way more details about the brain itself (you could never see on an x-ray).  They may also get a CT scan of the chest, abdomen and pelvis to make sure there isn’t an obvious tumor growing elsewhere.  Finally, to establish a diagnosis, doctors need a piece of the tumor.  This can be done by either biopsy, or directly with surgery (which brings us to the next section… treatment)

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Treatment:  The main treatment for GBM is surgery.  The general approach is to remove as much of the tumor as possible without causing any injuries, like stroke.  This is a judgment call and the extent of surgery is largely left up to the neurosurgeon.  Although commonly the best treatment strategy for new cases of GBM are discussed among a team of doctors.  This is called multidisciplinary care.  After surgery, patients receive radiation therapy which is high energy x-rays targeted at the area where the tumor was removed.  Radiation is delivered Monday through Friday, 5 days a week for a total of 30 treatments over 6 weeks.  Treatment is sometimes shorter for patients with difficulty traveling.  During radiation, patients take a chemotherapy pill called Temozolomide.  Following completion of radiation and chemo, patients go on and have chemotherapy alone for several months.  Finally, a newer innovative treatment called Tumor-Treating Fields, or TTF, uses a device attached to the scalp to disrupt cell division and extend the time until GBM grows back.

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Follow-up:  Unfortunately GBM is one of the most aggressive cancers, and it requires close follow up with doctors.  Typically patients are seen every 3 months for a regular history and physical exam to monitor for any changes, as well as an MRI of the brain to look for signs that the GBM has grown back.  Doctors may also order routine blood work, especially after chemotherapy.

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Recurrence:  There really are no great options for GBM that grows back.  When it grows back, it is called “recurrent glioblastoma”.  Some standard options include additional chemotherapy, more radiation, clinical trial treatment, steroids or simply transitioning to supportive care alone to keep patients comfortable.  Whenever possible, considering a clinical trial is a good option.  The benefits of a trial include helping future patients by establishing safety and effectiveness of new treatments.  Another potential benefit of enrolling on a trial is getting access to a treatment that may otherwise not be approved for public use outside the safety and controlled environment of a clinical trial.

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PRIMR Videos: We built a suite of videos to help patients and families navigate through the confusing pathways of brain tumors here.