Metformin and Prostate Cancer: What is the Evidence?

Abstract

INTRODUCTION: Prostate cancer (PCa) is the most prevalent cancer in males worldwide. Despite therapeutic advances, up to 30%-50% of patients experience recurrence. In recent years, the antineoplastic potential of metformin has been described in the incidence and prognosis of PCa. The aim of this review will be to assess the evidence on the use of metformin to reduce recurrence and increase survival in patients with PCa.
METHODS: The authors carried out a literature search in evidence-based medicine databases, including articles published between 01/2010 and 05/2022, in Portuguese and English. The MeSH terms used were “metformin”, “prostate cancer” and “therapy”. The level of evidence and strength of recommendation were assigned according to the Strength Of Recommendation Taxonomy (SORT) scale.
RESULTS: In the initial search, 17 articles were obtained, of which 3 meta-analyses were selected to carry out this review. All meta-analyses revealed a decrease in PCa recurrence in patients using metformin. The 3 meta-analyses also found an improvement in overall and PCa-specific survival in patients treated with metformin, however, only one of them showed a statistically significant association.
CONCLUSION: This review concluded, with a strength of recommendation B, that the use of metformin may have a positive impact on reducing recurrence and improving the survival of patients with PCa. However, it will be necessary to carry out more studies, with greater robustness and quality, to confirm this relationship.