RESUMO
PURPOSE: In rodents, a single exercise bout performed 24 h prior to a single doxorubicin treatment provides cardio-protection. This study investigated whether performing this intervention prior to every doxorubicin treatment for breast cancer reduced subclinical cardiotoxicity and treatment symptoms. METHODS: Twenty-four women with early stage breast cancer were randomly assigned to perform a 30-min, vigorous-intensity treadmill bout 24 h prior to each of four doxorubicin-containing chemotherapy treatments or to usual care. Established echocardiographic and circulating biomarkers of subclinical cardiotoxicity, as well as blood pressure and body weight were measured before the first and 7-14 days after the last treatment. The Rotterdam symptom checklist was used to assess patient-reported symptoms. RESULTS: The exercise and usual care groups did not differ in the doxorubicin-related change in longitudinal strain, twist, or cardiac troponin. However, the four total exercise bouts prevented changes in hemodynamics (increased cardiac output, resting heart rate, decreased systemic vascular resistance, p < 0.01) and reduced body weight gain, prevalence of depressed mood, sore muscles, and low back pain after the last treatment (p < 0.05) relative to the usual care group. No adverse events occurred. CONCLUSIONS: An exercise bout performed 24 h prior to every doxorubicin treatment did not have an effect on markers of subclinical cardiotoxicity, but had a positive systemic effect on hemodynamics, musculoskeletal symptoms, mood, and body weight in women with breast cancer. A single exercise bout prior to chemotherapy treatments may be a simple clinical modality to reduce symptoms and weight gain among women with breast cancer.