What is an ependymoma?
Ependymoma is a rare type of brain tumor that arises from glial cells of the central nervous system (CNS) that comprise astrocytes, oligodendrocytes and ependymal cells. The World Health Organization (WHO) Classification of Tumors of the CNS recognizes malignant brain tumors that arise from all three types of glial cell (i.e., astrocytomas, oligodendrogliomas and ependymomas). Ependymomas are found throughout the CNS in the supratentorial (ST), posterior fossa (PF) and spinal (SP) compartments and they affect both pediatric and adult populations.
How are ependymomas classified?
Researchers classify ependymomas based on the degree of variability in a tumor cell’s appearance (pleomorphism), the number of tumor cells proliferating (undergoing mitosis), crowding of the tumor cells (increased cellularity) and the amount of tumor infiltration (invasion) into surrounding brain tissue.
The WHO classifies ependymomas into a low-grade variety named “ependymoma” (also called a “WHO grade II ependymoma”) and a more malignant type called “anaplastic ependymoma,” also classified as a “WHO grade III ependymoma”. See our Pathology page for more information.
What age groups do ependymomas affect?
Although relatively uncommon, the disease can occur in any age group. Tumors of the posterior fossa are much more common in the pediatric population, and spinal cord tumors are more common in young to middle-age adults. Anaplastic ependymomas are more common in adults.
What treatment is available for an individual diagnosed with an ependymoma?
Currently, the standard therapy for a low-grade ependymoma includes total surgical excision followed by radiation therapy. Complete surgical resection is often not possible due to tumor location and concerns about damaging the surrounding eloquent brain during surgery. The situation is even more critical for patients with anaplastic ependymoma because of the higher proliferative (growth) rate and greater propensity for tumor infiltration into the surrounding normal brain, preventing any possibility of complete tumor removal by surgery.
For patients with the more aggressive anaplastic ependymoma, chemotherapy is often administered either before or after the radiation in the hope that infiltrating tumor cells will be eliminated. See our Treatment section for more details.
What happens if there is a recurrence of ependymoma?
Patients with recurrent tumors face a difficult challenge. When possible, patients undergo surgical re-resection of tumor. This often provides symptom improvement, reduces the tumor burden and confirms the presence of the tumor (as opposed to treatment-related necrosis) and the histologic grade (II versus III). However, radiation therapy is often not administered due to concerns about injuring the surrounding normal brain or spinal cord tissue. Therefore, treatment for recurrent ependymomas and anaplastic ependymomas relies on chemotherapy regimens.
Conventional chemotherapy, also known as cytotoxic chemotherapy, has been a mainstay of cancer treatment for several decades. However, although there are reports that a variety of chemotherapy agents have been shown to have activity against ependymomas, there are no established standard regimens. The CERN is actively investigating new treatment regimens and is developing new treatment agents to improve the options for patients with regrowing ependymomas.