A Brief History of Ependymoma – How Looking Back Can Help Create a Roadmap Forward

A recent publication, “A Brief History of Ependymoma,” published in the leading journal, Neuro-Oncology, serves to create an information base for clinicians and scientists new to the field, as well as for experienced providers looking to create a plan for the next series of research and clinical trials for ependymoma. CERN Executive Director, Kim Wallgren, was among the authors of this important paper.

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Overview of Ependymoma

For a long time, little was known about ependymoma, and researchers didn’t know as much about the biology of the disease compared to other types of cancer. Thus, to orient readers, the paper begins with a review of ependymoma basics. 

This overview notes that ependymoma is a biologically and clinically heterogeneous group of glial tumors that can occur throughout the central nervous system (brain or spinal cord) in patients of all ages. Most common in children when it is in the brain and more common in adults when it is in the spinal cord.

Ependymoma is not only rare but also a very complex disease. There is often uncertainty regarding the classification and treatment of ependymoma amongst health care professionals, particularly at centers that do not regularly treat patients with ependymoma. 

How Our Knowledge Changed Over Time

By going back to the very start of ependymoma research and working through every clinical trial and diagnostic development that has been achieved, the paper provides a solid information base to guide clinicians and researchers in their daily work. 

While ependymoma has been historically understudied for decades, recent years have seen major progress in understanding its biological underpinnings and clinical features. A primary focus is the development of classification models over time, evolving into the current molecular classification system, which identifies at least 10 distinct groups.

• The Early Days: Doctors first started writing about these tumors in the mid-1800s. They used microscopes to look at the cells and noticed they sometimes formed pretty, circular patterns called “rosettes.”
  
• The Middle Years: Scientists tried many different ways to group these tumors to figure out which ones were more dangerous. They even tried using things like viruses to explain how they grew.
  
• The Modern Breakthrough: In just the last few years, scientists have made a huge leap forward. Instead of just looking at how the cells appear under a microscope, they began taking into account the unique genetic and molecular features of the tumor cells. They discovered that there aren’t just one or two types of ependymoma, but many different “subgroups” that all behave differently and likely need different treatment approaches.

Current Treatment Standards

The review then discusses key clinical trials that established the current gold standard for therapy: maximal safe resection followed, in most cases, by radiotherapy. Right now, the best way doctors treat this is by having a neurosurgeon with expertise in primary brain and spine tumors carefully remove as much of the tumor as possible, and then typically refer for radiation therapy after. Scientists are still working hard to find better treatment strategies for patients with ependymoma, as current treatments are often not curative or without impacts on quality of life. Especially in situations in which the tumour grows back after the initial therapy, treatment options beyond repeated surgery and radiation therapy are currently very limited.

Looking Ahead

The molecular classification of ependymoma represents an asset for designing the next generation of ependymoma trials. However, it also raises new challenges that need to be addressed. The review highlights a few of these barriers, such as pre-clinical modeling difficulty, heterogeneity of the disease, lack of surgical standards across local providers, and the uncertainty of the role of conventional chemotherapy.

• Therapeutic Gap: The authors note that evidence for effective drug treatments and chemotherapies remains sparse.
  
• Upcoming Data: New insights are expected from recently finalized multi-institutional trials, such as SIOP EP II in Europe and ACNS0831 in North America, through metadata analysis.
  
• Ongoing Challenges: The paper concludes by discussing the remaining challenges in finding definitive cures for all types of ependymal tumors and expresses the urgent need for clinical trials that span across ages and subgroups.

Why This Matters

Even though we have learned more in the last 10 years than in the 100 years before that, there is still no definitive cure for many cases of ependymoma. Scientists are currently finishing large international studies to see if new treatments can help more kids and adults get better.

“It is fascinating to see how many famous doctors and scientists have conducted research on ependymoma at some point in their careers,” said one of the paper’s authors, David Ghasemi, MD, MRes. “The pathologist Rudolf Virchow, who is considered the father of modern medicine; the founders of the first systematic brain tumour classification, Harvey Cushing and Percival Bailey; and the famous physician Gustave Roussy, after whom one of Europe’s largest cancer centers is named; all studied ependymoma at some point in their careers. In ependymoma research, we stand on the shoulders of giants.”

Another key aspect the article highlights is the influential role that advocacy played and continues to play in accelerating our understanding of the disease. 

“I am particularly proud that Kim contributed to our review as an author and highlighted the central role played by philanthropic foundations such as CERN,” continued Dr. Ghasemi. “I already knew that we owe much of our progress to our patients’ foundations, but prior to writing this article, I was unaware of the sheer number of milestones in ependymoma research that CERN, in particular, has been instrumental in achieving.” 

The history of ependymoma research is a great example of how disease-specific research funding that is driven by patient organizations is imperative to generate momentum in scientific discovery, to build a base of expert clinicians and scientists, and to incentivize them to stay in the field. Furthermore, initial grants by smaller patient organizations frequently open doors for larger grants to build on these initial investments.

“We hope that our article will enable readers to find clinical studies that are relevant to the care of their individual patients and to better understand the complex interplay between classical histological and modern molecular diagnostics in the context of ependymoma treatment,” said Wallgren. “Of course, we also hope that this review provides an easy introduction to the fascinating world of ependymoma research and offers a good starting point for newcomers to the field. The review comes at an opportune time, as we celebrate 20 years of impact at CERN in 2026.”