The Epidemiology of Adipokines in Barrett's Esophagus

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DESCRIPTION (provided by applicant): The incidence of esophageal adenocarcinoma (EAC) is rising faster than that of any other cancer, and the 5- year mortality of this cancer type is 86%. The long-term career objective of the candidate is to develop novel cost-effective strategies for preventing mortality from EAC. Any such strategy will depend on identifying patients at risk for EAC. Barrett's esophagus (BE) is the accepted precursor of EAC. The immediate career objective is to develop novel strategies of identifying patients at risk for BE for the purpose of screening. Obesity is a risk factor for BE and EAC. Others have proposed that this effect is mediated by a mechanical effect promoting gastroesophageal reflux disease. We believe it is unlikely that the risk is due solely to such a mechanical effect; instead, we propose that visceral adipocytes secrete cytokines (adipokines) that promote BE and EAC. Adiponectin, an adipokine whose serum levels are inversely correlated with obesity, inhibits inflammation and promotes apoptosis; deficiency is associated with a number of epithelial cancers. The high molecular weight (HMW) form of adiponectin may be the metabolically active form. We hypothesize that adiponectin deficiency (and the HMW isoform in particular) is closely associated with BE, and is associated with progression of BE toward EAC. We propose a prospective case-control study to estimate the relation between adiponectin in plasma and BE, controlling for potential confounding factors. In addition to examining a potential mechanism to explain the effect of obesity on BE, we hope to identify in adiponectin deficiency a new biomarker of high risk for development of BE. The proposed translational study addresses priorities identified by the National Cancer institute, including to identify "pathophysiologic consequences of reflux, and its interrelationship with BMI, fat distribution, and other factors in the development of esophageal and gastric cardia adenocarcinomas and their precursors." The candidate's career will be developed through the mentored research experience and through didactic courses in epidemiology and bioinformatics. RELEVANCE: The incidence of esophageal adenocarcinoma is rising faster than that of any other cancer in the U.S. This highly fatal cancer is associated with obesity. This study tests the hypothesis that specific substances secreted from fat tissue are strongly associated with the risk of developing esophageal adenocarcinoma. If so, measurement of these substances may be useful in a screening program.