A clinical update on metformin and lung cancer in diabetic patients.

Diabetes mellitus (DM) is frequently increased in many countries and become a serious health problem worldwide. Diabetes is associated with dysfunction of different organs such as heart, eyes, blood vessels, nerves, and kidneys. There is a strong connection between diabetes and cancer. Metformin is one of the most commonly prescribed oral antidiabetic medicines and it is suggested as the first-line therapy due to its comparatively safe, inexpensive, effective and well-tolerated. Some of the in vitro and in vivo investigations proved that metformin may have a direct anticancer action by preventing the proliferation of malignant cells and formations of the colony, inducing arrest of cell cycle and apoptosis and suppressing tumor growth. The antiproliferative mechanism of metformin alone or in combination with various chemotherapeutic agents is complex and involves several beneficial roles. In this regard, clinical studies are required to explain these roles. In the coming future, the use of metformin, alone or in combination with current chemotherapy, might be a conventional approach to effectually manage lung cancer. This mini-review provides a critical overview of currently available clinical trials investigating the effects of metformin in lung cancer.