Anticancer activity of metformin: a systematic review of the literature

Background: The anticancer activity of metformin has been confirmed against several cancer types in vitro and in vivo. However, the underlying mechanisms of metformin in the treatment of cancer are not fully understood. This systematic review aims to discuss the possible anticancer mechanism of action of metformin. Method: A search through different databases was conducted, including Medline and EMBASE. Results: A total of 96 articles were identified of which 56 were removed for duplication and 24 were excluded after reviewing the title and abstract. A total of 12 research articles were included that describe different antiproliferative mechanisms that may contribute to the antineoplastic effects of metformin. Conclusion: This analysis discussed the potential anticancer activity of metformin and highlighted the importance of AMPK as a potential target for anticancer therapy. Lay abstract: Metformin is a widely used antidiabetic drug. It is the recommended treatment for Type II diabetes. Recently published reports claimed that the antidiabetic drug can also protect patients against cancer. This has led to a widespread interest in the antidiabetic medication as a possible treatment for cancer. While studies have confirmed the anticancer potential of metformin, the way in which metformin improves cancer outcome remains unknown. Hence, the current study investigates the reported mechanisms that explain how the antidiabetic drug works as an anticancer agent.