Mechanisms linking obesity and gastrointestinal cancers

Abstract

Introduction and purpose: The worldwide prevalence of obesity increased threefold between 1975 and 2016. Obesity is a risk factor for gastrointestinal cancers, including the pancreas, liver, esophagus, colorectum, stomach cardia, and gallbladder. This work is an analysis of the available PubMed literature on relationship between obesity and gastrointestinal cancers and possible mechanisms linking them.Brief description of the state of knowledge: There is a number of mechanisms responsible for obesity associated gastrointestinal cancers. Excess adiposity leads to: metabolic syndrome, chronic inflammation, altered production of steroid hormones and adipokines as well as changes in insulin and IGF1 signaling. This study examines the processes leading to obesity-associated colorectal, esophageal, gastric, and pancreatic cancers, which are known to be the most prevalent and lethal cancers worldwide. In this review, the mechanisms of gastrointestinal cancerogenesis such as changes in insulin and insulin-like growth factor signaling pathways, chronic inflammation associated to obesity, altered adipokine and inflammatory factors levels, are being discussed.Conclusions: Thorough understanding of the biological processes connecting obesity, metabolic health and gastrointestinal cancers may help to discover new risk factors and biomarkers, improve preventive strategies and invent ground-breaking treatment.Key words: obesity; gastrointestinal cancers; mechanisms of carcinogenesis.