Objective Therapeutic exercise is already used to ameliorate some of the side effects of cancer treatment. Recent studies examined its preventive potential regarding treatment-related toxicity, which can increase the risk of functional decline and lead to disease recurrence and death. This trial will examine whether the ATOPE (Tailored Therapeutic Exercise and Recovery Strategies) program, performed before treatment (ATOPE-B), can mitigate the onset and extent of cardiotoxicity beyond that achieved when the program is followed during treatment (ATOPE-I) in recently diagnosed breast cancer patients. Methods The intervention has a preparatory phase plus 12 to 18 sessions of tailored, high-intensity exercise, and post-exercise recovery strategies. 120 women recently diagnosed with breast cancer, in risk of cardiotoxicity due to anticancer treatment awaiting surgery followed by chemotherapy and/or radiotherapy, will be randomised to either group. In a feasibility study, measurements related to recruitment rate, satisfaction with the program, adherence to them, the retention of subjects, safety, and adverse effects will be explored. In the main trial, the efficacy of these interventions will be examined. The major outcome will be cardiotoxicity, assessed echocardiographically via the left ventricular ejection fraction. Other clinical, physical, anthropometric outcomes, biological and hormonal variables, will be also assessed after diagnosis, after treatment, 1 year after treatment ends, and 3 years after treatment ends. Conclusion Given its potential effect on patient survival, the mitigation of cardiotoxicity is a priority, and physiotherapists have an important role in this mitigation. If the ATOPE-B intervention returns better cardioprotection results, it may be recommendable that patients recently diagnosed follow this program.

BACKGROUND Therapeutic exercise is already much used as a means of ameliorating some of the side effects of cancer treatment. Recent studies have examined its preventive potential with respect to the appearance of treatment-related toxicity. Toxicity-induced cardiac damage - indeed, even temporary adverse effects on the heart - can increase the risk of functional decline, which can in turn lead to disease recurrence and death. OBJECTIVE The present trial will examine whether the ATOPE (Tailored Therapeutic Exercise and Recovery Strategies) program, performed before treatment starts for recently diagnosed breast cancer (ATOPE-B), can mitigate the onset and extent of cardiotoxicity beyond that achieved when the program is followed by similar patients who have already begun treatment (ATOPE-I), using a mobile app, ATOPE+, to determine women’s therapeutic exercise assimilation. METHODS The ATOPE intervention consists of 6 bouts of general preparatory exercise plus 12-18 bouts of tailored, high intensity exercise (whole-body and locoregional exercises), and the following of post-exercise recovery strategies (stretching and breathing exercises). A total of 120 female patients recently diagnosed with stage 1-IIIb breast cancer and awaiting surgery followed by chemotherapy and/or radiotherapy, and at risk of cardiotoxicity as described by the American Society of Clinical Oncology Guidelines, will be randomised 1:1 to either ATOPE-B or ATOPE-I. In a small feasibility study performed before the main trial, and lasting one full cycle of the ATOPE program, measurements related to recruitment rate, satisfaction with the application, satisfaction with the ATOPE-B and ATOPE-I programs, adherence to the program, the retention of subjects, safety, and adverse effects will be explored. In the main trial, which is designed to examine the efficacy of these interventions, the major outcome variable will be cardiotoxicity, assessed echocardiographically via the left ventricular ejection fraction. This, along with other clinical, physical, and anthropometric outcomes, and biological and hormonal variables, will be assessed after diagnosis, 3 days before the third chemotherapy session, 1 year after treatment ends, and 3 years after treatment ends. RESULTS Not aplicable CONCLUSIONS The left ventricular ejection fraction is modified by cancer treatment. Given its potential effect on patient survival, the mitigation of cardiotoxicity is a priority. If the ATOPE-B intervention returns better cardioprotection results than ATOPE-I, it may be recommendable that patients yet to begin treatment for breast cancer, follow this program. CLINICALTRIAL ClinicalTrials.gov, NCT03787966