title: Obesity Biomarkers, Metabolism and Risk of Cancer: An Epidemiological Perspective.
abstract: Obesity is associated with metabolic alterations that may pose a biological link between body fatness and risk of cancer. Elucidating the role of obesity-related biomarkers in cancer development is essential for developing targeted strategies aiming at obesity-associated cancer prevention. Molecular epidemiological studies of the past decades have provided evidence that major hormonal pathways linking obesity and cancer risk include the insulin and insulin-like growth factor-1 (IGF-1) axis, sex-steroid hormones, adipokines and chronic low-grade inflammation. These pathways are interrelated with each other, and their importance varies by obesity-related cancer type. The insulin/IGF-1 axis has been implicated to play an important mediating role in the association between obesity and risk of pancreatic, colorectal and prostate cancer. Endogenous sex-steroid hormone concentrations, in particular obesity-associated pre-diagnostic elevations of estrogens and androgens, play an important role in postmenopausal breast cancer and endometrial cancer development. The adipokines adiponectin and leptin and adipocyte-mediated chronic low-grade inflammation represented by the acute-phase C-reactive protein may explain a substantial part of the association between obesity and risk of colorectal cancer. There is less evidence on whether these hormonal pathways play a mediating role in other obesity-associated types of cancer. In this chapter, the molecular epidemiologic evidence from prospective studies relating circulating obesity-related biomarkers to cancer risk is summarized, taking into account available evidence from Mendelian Randomization investigations aiming at improving causal inference.
authors.affiliation: Molecular Epidemiology Research Group, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125, Berlin, Germany. katharina.nimptsch@mdc-berlin.de.
authors.forename: Katharina
authors.initials: K
authors.lastname: Nimptsch
authors.affiliation: Molecular Epidemiology Research Group, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125, Berlin, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Pischon
mesh_terms: D054392:Adipokines / Q000378:metabolism*; D000273:Adipose Tissue / Q000378:metabolism* / Q000503:physiopathology; D050154:Adiposity; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002471:Cell Transformation, Neoplastic / Q000378:metabolism* / Q000473:pathology; D004734:Energy Metabolism; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D009369:Neoplasms / Q000453:epidemiology* / Q000378:metabolism / Q000473:pathology; D009765:Obesity / Q000453:epidemiology* / Q000378:metabolism / Q000503:physiopathology; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors; D015398:Signal Transduction
chemical_list: D054392:Adipokines; D014408:Biomarkers, Tumor; D018836:Inflammation Mediators
keywords: Adipokines; Biomarkers; Cancer; IG-1; Inflammation; Insulin; Metabolism; Obesity; Sex-steroid hormones