Addition Of Hormonal Treatment Does Not Exacerbate Side-effects Or Responsiveness To Exercise Training In Breast Cancer Patients

The most common types of breast cancer (BC) involve a mutation in various hormone receptors. The standard of care for these patients includes chemotherapy (CT), radiation therapy (RT), and hormonal therapy (HT) that often results in a decline in physiological function. PURPOSE: Exercise has been shown to attenuate the physiological decline in patients undergoing CT and RT, and the purpose of this study was to explore these effects in patients undergoing additional HT. METHODS: A total of 225 BC patients that completed 12 weeks of exercise training at the University of Northern Colorado Cancer Rehabilitation Institute were included in this study. Participants were divided into two groups based on whether they received HT (HT, n = 74) or did not receive HT (NHT, n = 151) in addition to CT or RT. Physiological and psychological outcome measures were assessed at baseline (pre) and after (post) the exercise intervention and analyzed using paired and unpaired student’s t-tests. RESULTS: Exercise significantly (p < 0.001) improved estimated peak oxygen uptake (VO2peak), lower body strength-to-weight ratio (SWR), and upper body SWR from pre to post in both groups (HT: 21.5 ± 7.4 vs. 24.6 ± 7.1 mL/kg/min, 1.01 ± 0.35 vs 1.22 ± 0.45 lower SWR and 0.37 ± 0.16 vs 0.45 ± 0.17 upper SWR; NHT: 22.3 ± 6.9 vs. 25.2 ± 6.8 mL/kg/min, 1.03 ± 0.42 vs 1.28 ± 0.48 lower SWR and 0.30 ± 0.20 vs. 0.42 ± 0.21 upper SWR), as well as the number of chair squat repetitions (HT:15 ± 9 vs. 20 ± 11, NHT: 20 ± 14 vs. 30 ± 15). Exercise significantly improved handgrip strength in HT (pre vs post: 25.3 ± 6.3 vs. 26.9 ± 6.4 kg, p < 0.05), but not in NHT (pre vs. post: 24.9 ± 7.3 vs. 25.0 ± 6.7 kg, p = 0.77). Exercise significantly decreased perceived fatigue and depression levels in both groups (p < 0.0001). There were greater baseline fatigue and post-intervention depression levels in NHT compared to HT (p < 0.05). The addition of HT did not significantly affect baseline or post-intervention VO2peak or SWRs. CONCLUSIONS: While there were between group differences in fatigue and depression, both groups responded similarly to exercise training. Overall, these data suggest that for BC patients the addition of HT does not exacerbate treatment-related declines in functional capacity and does not appear to alter their responsiveness to exercise training when compared to patients who do not receive HT.