Does resection improve surgical outcomes over biopsy in elderly patients with newly-diagnosed Glioblastoma? A Meta-analysis of 18,317 patients.

Introduction: Glioblastoma (GBM) is the most common primary malignant brain tumor. Maximal-safe surgical tumor resection has been shown to improve clinical outcomes in elderly patients with GBM over biopsy. However, most of the evidence is limited to observational studies. The first clinical trial comparing biopsy with resection of surgically-accessible GBM in elderly shows that while quality of life is improved by resection, it does not improve survival. A meta-analysis is essential to assess the efficacy of resection in this population.

Methods: A database search was conducted until October 9th, 2023, to identify published studies reporting the clinical outcomes of GBM patients >60 years undergoing resection or biopsy. Primary outcomes were overall survival (OS), progression-free survival (PFS), and post-surgical complications.

Results: Out of 781 articles, 14 retrospective cohort studies and 1 randomized controlled trial met our inclusion criteria, considering 18,317 patients for analysis. Patients undergoing surgical resection had an OS mean difference (MD) of 7.27 months (0.04-14.49, p=0.05) over biopsy, with a reduced mortality rate HR=0.50 (0.38-0.65, p= < 0.00001). The PFS MD was 2.3 months (0.79-3.89, p=0.003) higher in the resection group, and the risk of recurrence was lower with surgery HR=0.50 (0.37-0.68, p= < 0.00001). The complication risk ratio (RR) remained comparable among groups RR=1.35 (0.85-2.14, p=0.20).

Conclusion : This meta-analysis shows that resection improves GBM outcomes compared to biopsy, though most of the studies were observational cohorts. The only available clinical trial which compared surgically-accessible tumors and quality of life identified no survival benefits. This study highlights the need to better identify patients who are optimal candidates for either surgical resection or biopsy and to consider other outcome measures beyond survival in elderly patients.