Bevacizumab for recurrent glioblastoma: a systematic review and meta-analysis

OBJECTIVE: The phenomenon is that few randomized control trials (RCTs) directly compared the effects of bevacizumab with other types of standard treatments for recurrent glioblastoma (GBM). We conducted a systematic review and meta-analysis to assess the efficacy of bevacizumab in recurrent GBM patients. MATERIALS AND METHODS: We searched electronic databases (Medline, Embase. and Web of Science) contrasting the bevacizumab with standard treatments up to May 2021. For the continuous outcomes of median progression-free survival (PFS) and median overall survival (OS), we summarized the mean difference (MD) as the effective index. We used relative risk (RR) to estimate the data with a random-effects model to get the outcomes of objective response rate (ORR), 12-month OS, 6-month PFS, and any mentioned adverse events. RESULTS: A total of 807 patients in 5 RCTs included into our systematic review and meta-analysis. The results showed bevacizumab could provide benefits of the ORR (RR, 2.67: 95% CI: 1.14-6.26, p = 0.02), median PFS (MD, 1.12 months; 95% CI: 0.35-1.90 months, p = 0.005), but not the median OS (MD, -0.19 months; 95% CI: -1.37-0.99 months, p = 0.75). Whereas the rates of the secondary outcomes of interest were similar between the bevacizumab group and control group, including 6 month-PFS (RR, 1.23; 95% CI, 0.82-1.84, p = 0.32) and 12 month-OS (RR, 0.93; 95% CI, 0.79-1.09, p = 0.36). As for adverse events, patients with bevacizumab showed higher rates of grade 3/4 and any grade hypertension compared with those with standard treatments (RR, 3.71; 95% CI: 1.17-11.76, p = 0.03; RR, 2.68; 95% CI: 1.26-5.76, p = 0.01, respectively). CONCLUSIONS: This study provides clear proof of the beneficial effects of bevacizumab treatment in recurrent GBM patients. The only observed adverse event was grade 3/4 or any grade hypertension.