Review: Diabetes, Obesity and Cancer - Pathophysiology and Clinical Implications.

Abstract

Obesity and diabetes have both been associated with an increased risk of cancer. In the face of increasing obesity and diabetes rates worldwide, this is a worrying trend for cancer rates. Factors such as hyperinsulinemia, chronic inflammation, anti-hyperglycemic medications and shared risk factors have all been identified as potential mechanisms underlying the relationship. The most common obesity- and diabetes-related cancers are endometrial, colorectal and post menopausal breast cancers. In this review, we summarize the existing evidence that describes the complex relationship between obesity, diabetes and cancer focusing on epidemiologic and pathophysiologic evidence, also reviewing the role of anti-hyperglycemic agents, novel research approaches such as Mendelian Randomization as well as methodologic limitations of existing research. In addition, we also describe the bi-directional relationship between diabetes and cancer with a review of the evidence summarizing the risk of diabetes following cancer treatment. We conclude this review by providing clinical implications that are relevant for caring for patients with obesity, diabetes and cancer and provide recommendations for improving both clinical care and research for patients with these conditions.