Type 2 Diabetes and Cancer: An Overview of Epidemiological Evidence and Potential Mechanisms

Epidemiological studies have demonstrated an association between type 2 diabetes (T2DM) and the development of different types of cancer including those of the liver, pancreas, endometrium, colon and rectum, breast, and bladder. The association between T2DM and cancers may partly be due to shared common risk factors of these pathologic conditions and/or anti-diabetic treatments. Hyperglycemia and hyperinsulinemia, two important features of T2DM, are more clinically relevant factors in cancer development. Other factors, including the increased levels of insulin-like growth factor, steroid and peptide hormones, oxidative stress, and inflammatory markers, are also involved in the connection between T2DM and cancer. This review provides a brief overview of the epidemiological evidence supporting the association of T2DM and cancer and discusses the most important potential causes.