Teaching an old drug new tricks: metformin as a targeted therapy for lung cancer.

Identifying novel drugs for treatment of lung cancer remains of utmost importance, and, in recent years, targeted therapies have been acknowledged as particularly attractive. Metformin, a commonly prescribed oral hypoglycemic agent, has known effects on the mammalian target of rapamycin pathway, ultimately resulting in downstream inhibition of cellular growth and proliferation. In a recent article (Memmott RM, Mercado JR, Maier CR, et al: Metformin prevents tobacco carcinogen-induced lung tumorigenesis. Cancer Prev Res (Phila) 3:1066-1076, 2010), Memmott et al assessed the utility of metformin in an in vivo model of tobacco carcinogen-induced lung cancer. The authors show that tumor burden is decreased in animals administered metformin, suggesting that this drug may have promising potential for the treatment and chemoprevention of lung cancer.