Purpose: Glioblastoma multiforme (GBM) is a highly aggressive cancer with limited survival despite current treatments. Rising treatment costs highlight the importance of identifying more affordable therapeutic alternatives. A body of literature has shown that metformin has the potential to act as an antineoplastic agent. Here, we examined the effects of metformin on GBM in humans. Methods: The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed to perform the review. A total of 469 studies were screened using comprehensive search terms. Of these, 4 studies were compatible for the meta-analysis. Results: Data analysis demonstrated an increase in median overall survival for GBM patients up to 18 months compared to controls (p = 0.00197). Conclusions: Overall, our findings support the efficacy of metformin as an anti-neoplastic agent, and that it may grant a survival advantage for patients diagnosed with GBM. Further analyses should find dose-dependent relationships between metformin and the targeted survival outcomes in larger, rigorous clinical trials.
Gonzales-Portillo et al. (Tue,) studied this question.