# Validation of Preoperative Neoadjuvant Bevacizumab Therapy for Newly Diagnosed Glioblastoma via Comparative Analyses with Propensity Score Matching

## TL;DR

This study finds that preoperative bevacizumab does not improve survival in newly diagnosed glioblastoma but may help in specific cases by improving functional status.

## Contribution

The study provides new evidence on the limited survival benefit and potential contextual utility of preoperative bevacizumab in glioblastoma.

## Key findings

- Preoperative bevacizumab did not improve progression-free or overall survival compared to standard therapy.
- Preoperative bevacizumab was associated with improved postoperative functional status.
- Greater reduction in contrast-enhanced tumor volume correlated with better survival outcomes.

## Abstract

Bevacizumab is widely used in the treatment of glioblastoma, although its role in newly diagnosed disease remains controversial. In this study, we evaluated the clinical impact of preoperative neoadjuvant bevacizumab by comparing perioperative and survival outcomes with those of patients treated with standard chemoradiotherapy using propensity score matching. Preoperative bevacizumab did not improve progression-free or overall survival compared with standard therapy. However, exploratory imaging analyses suggested that a greater reduction in contrast-enhanced tumor volume on magnetic resonance imaging was associated with more favorable survival outcomes, although these findings require external validation. Significantly, preoperative bevacizumab was associated with improved postoperative functional status, suggesting a potential role in optimizing perioperative conditions. These results indicate that neoadjuvant bevacizumab should not be used routinely in newly diagnosed glioblastoma, but may have a contextual role in selected patients for whom perioperative factors—such as extensive edema, lower performance status, or tumor involvement of eloquent brain regions—complicate immediate surgical management.

Background/Objectives: The role of preoperative neoadjuvant bevacizumab (neoBev) in newly diagnosed glioblastoma (GB) remains controversial. We evaluated its impact on perioperative and survival outcomes and explored imaging-based associations with prognosis. Methods: We retrospectively analyzed 33 patients with newly diagnosed GB who received preoperative neoBev (10 mg/kg; surgery performed 21–30 days later). A matched control cohort of 33 patients treated with standard chemoradiotherapy was selected using propensity score matching. Changes in Karnofsky Performance Status (KPS), extent of resection, and volumetric alterations on gadolinium-enhanced T1-weighted MRI (T1Gd) and FLAIR were assessed. Progression-free survival (PFS) and overall survival (OS) were compared. Results: All patients had GB (31 IDH-wild-type, 2 IDH-mutant). Median KPS improved after neoBev (71 to 83), while no improvement was observed in controls. After matching, median PFS and OS did not differ between the neoBev and control groups (7.4 vs. 8.6 months and 13.4 vs. 13.8 months, respectively). Exploratory analyses in the neoBev cohort showed that greater T1Gd volume reduction was associated with improved PFS and OS, whereas FLAIR changes were not. Conclusions: Preoperative neoBev did not improve survival compared with standard chemoradiotherapy. However, it was associated with improved functional status, and exploratory imaging findings suggested associations between early radiographic response and outcome. NeoBev should not be used routinely but may have a contextual role in selected patients with perioperative challenges.