gms | German Medical Science

Objective: The management of patients with glioblastoma (GBM) involving the Corpus callosum (ccGBM) remains challenging and no standard treatment concerning the implementation of surgical and adjuvant therapeutic options has been established so far. The aim of this study was to evaluate clinical, imaging and molecular outcome predictors in patients with ccGBM. Additionally, the correlation of surgical and adjuvant treatment with survival was assessed.

Methods: A retrospective analysis of patients with GBM treated at our department from 2008 to 2018 were enrolled in the study. Overall survival (OS) was defined as the time from the date of presentation to the date of death. Progression free survival (PFS) was calculated from the date of presentation to the date of first tumor progression on imaging. The extent of resection and the adjuvant treatment regime were documented. Imaging criteria as well as molecular markers (MGMT, IDH1, Ki67, p53) were further assessed. The data were analyzed using Python 3.7 (Python Software Foundation, Wilmington, Delaware). Survival analysis was done using Kaplan–Meier curve and significance determined by the log-rank test. Significant factors were further analyzed using multivariate analysis. A p-value < 0.05 was considered significant.

Results: A total of 78 patients with ccGBM were included. The mean age was 52.1 years (range 24-88), 57.7% (45/78) were male and 42.3% (33/78) were female. The mean pre-treatment Karnofsky Performance Status (KPS) was 74.0% (range 60-100). The extent of resection was as followed: biopsy in 53.3% (40/78), partial resection (PR) in 10.7% (8/78), and GTR in 36% (27/78). The mean PFS was 8.1 months (range 1-47) and the mean OS was 13.6 months (range 1-88). Significant predictors of OS were tumor volume (p=0.05), involvement of basal ganglia (p=0.05), the extent of resection (p=0.002) and the PFS (p<0.0001). Tumor contact to the ependyma was associated with worse OS, the result did not reach statistical significance (p=0.07). We found no correlation of survival with the adjuvant treatment or molecular parameters.

Conclusion: Although the survival of patients with ccGBM is still poor, GTR leads to a survival benefit and should be considered as a treatment option, if achievable under consideration of other tumor characteristics, such as ependyma contact or involvement of the basal ganglia.