Title:Metformin has no Significant Anticancer Effect on Patients with Advanced or
Unresectable Cancer: A Systematic Review and Meta-analysis
Volume: 28
Issue: 16
Author(s): Xinyan Gan, Chang Cao, Yan He, Xiaolin Hu, Xingchen Peng and Yonglin Su*
Affiliation:
- Rehabilitation Medicine Center and Department of Biotherapy, West China Hospital, Sichuan University,
Chengdu, China
Keywords:
Metformin, cancer, randomized clinical trials, overall survival, progression-free survival, meta-analysis.
Abstract:
Background: At present, the antitumor effect of metformin is controversial. Previous meta-analyses
included observational studies, of which the results can be influenced by many confounders, affecting the result of
meta-analyses and weakening the strength of evidence. Therefore, we conducted a meta-analysis to confirm the effect
of metformin use on patients with advanced or unresectable cancers, including randomized clinical trials (RCTs).
Methods: We searched for RCTs in accordance with the inclusion and exclusion criteria. A meta-analysis was
conducted to combine hazard ratios (HRs) or risk ratios (RRs) and their 95% confidence intervals (CIs) using a
random-effects model.
Results: Finally, 7 eligible RCTs were included in the meta-analysis. Overall, the combined results revealed that
treatment with metformin did not improve the overall survival (OS) of patients (HR, 1.12; 95% CI, 0.91-1.37,
p>0.05), and there was no clear evidence that metformin use was related to improved progression-free survival (PFS)
(HR, 1.17; 95% CI, 0.97-1.40; p>0.05). The pooled RR for grade III or IV adverse events was 0.92 (95% CI, 0.52-
1.60; p>0.05), indicating that the use of metformin was not significantly related to increased toxicity.
Conclusion: Metformin does not significantly improve the survival of patients with advanced or unresectable
cancer, regardless of cancer type and region.
