Outcome and characteristics of patients with adult grade 4 diffuse gliomas changing sites of treatment.

Purpose: With increasing patient self-empowerment and participation in decision making, we hypothesized that patients with adult-type diffuse gliomas, CNS WHO grade 4 who change sites of treatment differ from patients being entirely treated in one neuro-oncological center.

Methods: Prospectively collected data from all diffuse glioma grade 4 patients who underwent treatment in our neuro-oncological center between 2012 and 2018 were retrospectively examined for differences between patients having initially been diagnosed and/or treated elsewhere (External Group) and patients having entirely been treated in our neuro-oncological center (Internal Group). Additionally, a matched-pair analysis was performed to adjust for possible confounders.

Results: A total of 616 patients was analyzed. Patients from the External Group (n = 78) were significantly younger, more frequently suffered from IDH-mutant astrocytoma grade 4, had a greater extent of tumor resection, more frequently underwent adjuvant therapy and experienced longer overall survival (all p < 0.001). However, after matching these patients to patients of the Internal Group considering IDH mutations, extent of resection, adjuvant therapy, age and gender, no difference in patients' overall survival was observed anymore.

Conclusion: The present study demonstrates that mobile diffuse glioma grade 4 patients stand out from a comprehensive diffuse glioma grade 4 patient cohort due to their favorable prognostic characteristics. However, changing treatment sites did not result in survival benefit over similar patients being entirely taken care of within one neuro-oncological institution. These results underline the importance of treatment and molecular markers in glioma disease for patients' self-empowerment, including changing treatment sites according to patients' needs and wishes.