Onkologie und Sport

Abstract

Introduction: Epidemiologic and controlled clinical studies have shown that exercise training before, during and after a cancer therapy can have a substantial impact on therapy- and cancer-related symptoms. Further research investigated whether the benefits can be extended to cancer progression, recurrence, and cancer-specific or overall mortality. The underlying biological mechanisms are presumably complex, and may be specific for different types of training and cancer. Methods: A systematic PubMed-based literature review on the effects of exercise training on biomarkers in adult cancer patients was conducted till November 2013. Results: A total of 25 publications on 6 cancer sites were identified. Different biologic mechanisms on the effects of exercise trainings were discussed. Profound hypotheses included the modulation of metabolic factors, immune function, pro- and anti-inflammatory processes, sex hormones, and DNA repair capacities and oxidative stress. Most studies investigated breast cancer patients, endurance training, and changes in metabolic and inflammatory parameters. Results for all mechanisms are inconsistent. Discussion: Compared to the complexity of the topic and due to the paucity of studies in cancer patients the current level of evidence needs to be classified as preliminary. Future well-powered exercise intervention trials with cancer patients should, if feasible, incorporate translational and hypotheses-driven biomarker research. For clinical practice, these identified limitations of knowledge on mechanisms should not slow the increasing acceptance of physical training as safe, well-tolerated and highly effective supportive cancer therapy.Key Words: Biological mechanisms, exercise training, cancer, clinical studies