Diabetes and cancer: Epidemiologic and physiopathogenic links

Diabetes and cancer are two complex and multifactorial conditions, which incidence and prevalence are rising around the world. With significant associated morbidity and mortality, their combination does not seem to be only epidemiologic but also involves physiopathogenic underneaths. It leads to an elevated risk in incidence and prognosis of various cancers in diabetic patients. Several phenomenons described in diabetes such as hyperglycemia, insulinoresistance, and an inflammatory state participate in carcinogenesis. Epigenetic defects as deoxyribonucleic acid (DNA) methylation, histone post-translational changes and micro-ribonucleic acid (micro-RNA) is a possible explanation, making the link between metabolic and inflammatory abnormalities and carcinogenesis. The occurrence of hepatocellular carcinoma (HCC) is mediated by non-alcoholic steatosisdisease (NAFLD) which is the hepatic expression of metabolic syndrome. It is first cancer related cause of death in diabetic patients. Its incidence is increasing since type 2 diabetes (T2D) and associated metabolic disorders are in progression, as hypertension, obesity and sedentary lifestyle. Finally, antidiabetic treatments opened new fields of research, especially with metformin, whose anti-oncogenic effects demonstrated in experimental studies, have not been confirmed for use as adjuvant in anticancer therapies.