title: The Influence of Energetic Factors on Biomarkers of Postmenopausal Breast Cancer Risk.
abstract: Strong and consistent evidence exists that physical activity reduces breast cancer risk by 10-25 %, and several proposed biologic mechanisms have now been investigated in randomized, controlled, exercise intervention trials. Leading hypothesized mechanisms relating to postmenopausal breast cancer include adiposity, endogenous sex hormones, insulin resistance, and chronic low-grade inflammation. In addition, other pathways are emerging as potentially important, including those involving oxidative stress and telomere length, global DNA hypomethylation, immune function, and vitamin D exposure. Recent exercise trials in overweight/obese postmenopausal women implicate weight loss as a mechanism whereby exercise induces favorable changes in circulating estradiol levels and other biomarkers as well. Still it is plausible that some exercise-induced biomarker changes do not require loss of body fat, whereas others depend on abdominal fat loss. We highlight the latest findings from randomized, controlled trials of healthy postmenopausal women, relating exercise to proposed biomarkers for postmenopausal breast cancer risk.
authors.affiliation: Department of Population Health Research, CancerControl Alberta, Alberta Health Services, Quarry Park, c/o 10101 Southport Rd SW, Calgary, Alberta T2W 3N2 Canada.
authors.forename: Heather K
authors.initials: HK
authors.lastname: Neilson
authors.affiliation: Department of Population Health Research, CancerControl Alberta, Alberta Health Services, Quarry Park, c/o 10101 Southport Rd SW, Calgary, Alberta T2W 3N2 Canada.
authors.forename: Shannon M
authors.initials: SM
authors.lastname: Conroy
authors.affiliation: Department of Population Health Research, CancerControl Alberta, Alberta Health Services, Quarry Park, c/o 10101 Southport Rd SW, Calgary, Alberta T2W 3N2 Canada ; Department of Community Health Sciences, Faculty of Medicine, University of Calgary, 3330 Hospital Drive N.W., Calgary, Alberta T2N 4N2 Canada ; Department of Oncology, Faculty of Medicine, University of Calgary, 1331 29 St. N.W., Calgary, Alberta T2N 4N2 Canada.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Friedenreich
keywords: Adiposity; Biomarkers; Biomechanisms; Breast cancer; Estrogen; Exercise; Physical activity; Postmenopausal women; Randomized trials; Sex hormones; Weight loss