A review on the potential of repurposing of metformin for colon cancer and breast cancer

Abstract

Metformin, a hypoglycemic agent is currently being repurposed for the treatment of different types of cancer due to its pleiotropic functions, affordability, stability at room temperature with long shelf life, broadly favorable safety profile. Several potential mechanisms have been suggested for the ability of metformin to suppress cancer growth in vitro and vivo: activation of LKB1/AMPK pathway, inhibition of cancer cell growth by suppressing mTORC1, inhibition of Generation of ROS, reduction of IGF-1, and IGF-2, inhibition of chronic inflammation, activation of the immune system, modulation of ADORA1, and downregulation of gluconeogenesis in the mitochondria. However, by the in-dept summary and assessment of existing clinical data based on OS, PFS, HR, 95% CI in both CRC and BC, it can be said that metformin exhibits greater promise in CRC patients than the BC patients. The affirmation of the curative effect of metformin for the treatment in cancer will be greatly reinforced by comprehensive randomized clinical investigations on diverse participants. Of note, the data collected suggests that the daily dose of 1500–2000 mg of metformin is well tolerated and multiple clinical trials have reported promising results.