title: Every exercise bout matters: linking systemic exercise responses to breast cancer control.
abstract: Cumulative epidemiological evidence shows that regular exercise lowers the risk of developing breast cancer and decreases the risk of disease recurrence. The causality underlying this relation has not been fully established, and the exercise recommendations for breast cancer patients follow the general physical activity guidelines, prescribing 150 min of exercise per week. Thus, elucidations of the causal mechanisms are important to prescribe and implement the most optimal training regimen in breast cancer prevention and treatment. The prevailing hypothesis on the positive association within exercise oncology has focused on lowering of the basal systemic levels of cancer risk factors with exercise training. However, another rather overlooked systemic exercise response is the marked acute increases in several potential anti-cancer components during each acute exercise bout. Here, we review the evidence of the exercise-mediated changes in systemic components with the ability to influence breast cancer progression. In the first part, we focus on systemic risk factors for breast cancer, i.e., sex hormones, insulin, and inflammatory markers, and their adaptation to long-term training. In the second part, we describe the systemic factors induced acutely during exercise, including catecholamines and myokines. In conclusion, we propose that the transient increases in exercise factors during acute exercise appear to be mediating the positive effect of regular exercise on breast cancer progression.
authors.affiliation: Centre of Inflammation and Metabolism (CIM) and Centre for Physical Activity Research (CFAS), Rigshospitalet, Faculty of Health Science, Copenhagen University Hospital, 7641, University of Copenhagen, Blegdamsvej 9, 2100, Copenhagen, Denmark.
authors.forename: Christine
authors.initials: C
authors.lastname: Dethlefsen
authors.affiliation: Centre of Inflammation and Metabolism (CIM) and Centre for Physical Activity Research (CFAS), Rigshospitalet, Faculty of Health Science, Copenhagen University Hospital, 7641, University of Copenhagen, Blegdamsvej 9, 2100, Copenhagen, Denmark.
authors.forename: Katrine Seide
authors.initials: KS
authors.lastname: Pedersen
authors.affiliation: Centre of Inflammation and Metabolism (CIM) and Centre for Physical Activity Research (CFAS), Rigshospitalet, Faculty of Health Science, Copenhagen University Hospital, 7641, University of Copenhagen, Blegdamsvej 9, 2100, Copenhagen, Denmark. phojman@inflammation-metabolism.dk.
authors.forename: Pernille
authors.identifier: 0000-0003-1206-8574
authors.initials: P
authors.lastname: Hojman
mesh_terms: D000222:Adaptation, Physiological; D015415:Biomarkers; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D015444:Exercise; D005260:Female; D006801:Humans; D007107:Immune System / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D012307:Risk Factors; D013312:Stress, Physiological
chemical_list: D015415:Biomarkers
keywords: Acute exercise; Breast cancer; Chronic training; Systemic factors