Is Metformin a Treatment Opportunity for Colorectal Cancer?

Abstract

BACKGROUND Colorectal cancer (CRC) is one of the common deadly cancers worldwide. The incidence of CRC has been increasing nowadays and new therapy agents are still being investigated for the treatment. Metformin (1, 1-dimethyl biguanide), an oral antidiabetic drug from Galega officinalis mostly used in the treatment of type 2 diabetes, has gained considerable research interest in cancer prevention and therapy for many types of cancer including CRC. By targeting the specific pathways involved in cell differentiation, metabolism and metastasis, different mechanisms of action of metformin are tried to be elucidated using CRCs in studies. METHODS We searched 3 electronic bibliographic databases (Web of Science, PubMed, and Google Scholar) and research in progress using ClinicalTrials.gov from inception to September 20, 2019. Subject headings and key words included `metformin' and/or `metformin in colon cancer', and related terms, and various terms related to colon cancer treatment. RESULTS Although it seems justified on the basis of the results of a large number of studies, there is much we do not know about the effect of metformin on CRC. CONCLUSIONS In this review, we focused on studies showing the potential effects of metformin in CRC, especially its possible mechanisms of action in chemoprevention therapy for colorectal cancers.