The Effect of Adjuvant Chemoradiotherapy Initiation Time on Prognosis in Glioblastoma Multiforme

Objectives: To determine survival and investigate associated prognostic factors in glioblastoma multiforme (GBM) patients receiving adjuvant therapy. Materials and Methods: The study population comprised patients with isocitrate dehydrogenase wild-type GBM who were enrolled between 1 September 2022 and 1 March 2024. The primary endpoint was overall survival (OS), while the secondary endpoint was progression-free survival. Comparisons between groups were conducted using the log-rank test, and multivariate analyses were performed using Cox regression. Results: A total of 67 patients were evaluated. The median OS of patients was 19.3 months [95% confidence interval (CI) 15.1 to not reached (NR)]. A total of 60 patients (89.1%) underwent adjuvant treatment. The median OS was 31.1 months (95% CI 19.3 to NR) for patients treated within the first four weeks, 15.7 months (95% CI 15.1 to NR) for those treated within four to six weeks, and 11.3 months (95% CI 9.8 to NR) for those treated after six weeks. Conclusion: The observed survival rate in our study was comparable to that reported in clinical trials. However, the survival rate was significantly lower in patients who received treatment at a later stage. Therefore, further studies with larger patient populations are recommended to ensure that the guidelines more accurately reflect the timing of adjuvant therapy in GBM patients.