Oncodiabetology II. Antidiabetics and cancer prevention

Abstract

The number of patients with type 2 diabetes is increasing worldwide. In Hungary, the prevalence of known diabetic adults exceeds 9.1%, causing increased economical and medical burden to the society. It is obvious that there is a considerable urge to develop novel, safer and more efficient antidiabetic drugs. Therefore, studies have been focusing on the beneficial or detrimental side effects of antidiabetic drugs besides their general metabolic effects. Every anti-diabetic agent has an indirect anti-tumor effect as a consequence of lowering blood glucose levels and controlling carbohydrate, protein and lipid metabolism. In addition, most agents have their own direct antitumor effects, on the other hand, some may play a negligible role in cancer promotion. While the latter possibility is based mainly on pre-clinical, experimental data or on short-duration clinical studies, the informations about the safety of antidiabetic drugs are verified by large-scale, randomized, multicenter, placebo-controlled trials. Nowadays, metformin is the only drug that has been shown to reduce cancer risk in a variety of tumor localizations in monotherapy or in combination with other antidiabetic agents and insulins, and even in combination with certain cytostatics and biological therapies. The available data about the role of other antidiabetics in tumor prevention are less clear or insufficient. Here, we review the available – sometimes contradictory – literature about the relationship of tumor and antidiabet ics, verifying the safety of antidiabetics. Here, we propose that in the future tumor-specifically optimized antidiabetic treatment may play a role in tumor prevention or even in specific oncotherapy in patients with or without diabetes.