Dexrazoxane improves cardiac autonomic function in epirubicin-treated breast cancer patients with type 2 diabetes

OBJECTIVE The study objective was to investigate the protective effects of dexrazoxane (DRZ) on the cardiac autonomic nervous system (ANS) activity in anthracycline-treated breast cancer patients with diabetes. METHODS A total of 110 early stage breast cancer patients with type 2 diabetes were divided randomly into 2 even groups: chemotherapy alone (Chemo) and chemotherapy + DRZ (Chemo + DRZ). All patients underwent adjuvant chemotherapy (80 mg/m epirubicin and 500 mg/m cyclophosphamide) for a total of 6 cycles with 21 days/cycle. The Chemo + DRZ group patients were treated intravenously with 800 mg/m DRZ 30 minutes prior to the administration of epirubicin, while the Chemo group patients were given saline. The cardiac ANS function was evaluated for each patient before and after 6 cycles of chemotherapy by resting heart rate (RHR) and heart rate variability (HRV), which was evaluated by both time and frequency domains. RESULTS Before and after chemotherapy, patients in both groups showed significant decreases in HRV indices and increases in RHR and the low-frequency/high-frequency ratio. There were no significant differences between Chemo and Chemo + DRZ groups in terms of RHR and HRV indices before chemotherapy; however, after chemotherapy, patients in the Chemo group had a higher average RHR and lower HRV indices compared with patients in the Chemo + DRZ group. CONCLUSION DRZ protects the cardiac ANS in epirubicin-treated early stage breast cancer patients with diabetes.