An international clinical program for the diagnosis and treatment of children with ependymoma (SIOP-EP-II)

Ependymomas are rare malignant cancers of the central nervous system, meaning they affect the brain or spinal cord. They can occur at any age, but are more common in children and adolescents. The exact causes have not yet been clearly established. Currently, ependymomas are classified into WHO grades 1–3 based on their cellular structure. However, it has been shown that assessing risk based on factors such as tumor location and patient age is more appropriate. Treatment depends on the tumor’s location, the child’s age, and whether the tumor could be completely removed. Surgery to remove the tumor is usually performed first. Afterward, treatment depends on the success of the surgery. In the SIOP-EP-II study, patients are divided into three groups (known as “strata”): Stratum 1: Children older than 12 months with a completely removed tumor. They receive either radiation therapy or a combination of radiation therapy and chemotherapy. Stratum 2: Children older than 12 months whose tumor was not completely removed. They receive chemotherapy with or without high-dose methotrexate. This may be followed by another surgery or targeted follow-up radiation therapy, if necessary. Stratum 3: Children under 12 months of age or those who cannot receive radiation therapy. This group receives intensive chemotherapy. Some of the patients also receive the medication valproate, which may influence tumor growth. Within each of the three groups, there is a treatment group and a control group, into which patients are randomly assigned. Patients/parents and doctors know who is in which group and which medications are being taken. This is called an open-label study design.

The goal of the SIOP-EP-II study is to improve and standardize staging and treatment protocols for the respective patient groups. The study investigates which combination of surgery, chemotherapy, and radiation therapy yields the best results with as few side effects as possible. In addition, the study examines how often the tumor can be completely removed through surgery (known as complete tumor resection) and how long patients live without disease progression after the start of treatment (progression-free survival, PFS).

Children, adolescents, and young adults under the age of 22 who have recently been diagnosed with a brain ependymoma are eligible to participate in the SIOP-EP-II study. The diagnosis must have been confirmed by a histological examination and correspond to WHO tumor grade 2 or 3. Another requirement for study participation is that the patient has no other serious illnesses or acute infections that could prevent safe cancer treatment. Furthermore, the disease must not have spread to the spine (metastases).