Changes In Peak Oxygen Uptake, Ventilatory Anaerobic Threshold, And Power Output During Treatment Of A Stage II Breast Cancer Patient

PURPOSE: The purpose of this case study was to determine the changes in cardiorespiratory fitness that resulted from chemotherapy and radiation treatment in a Stage II breast cancer patient participating in cardio-oncology rehabilitation (CORE). METHODS: A 46-yr-old, female with recently diagnosed estrogen receptor positive (ER +) human epidermal growth factor receptor 2 gene negative (HER2-), stage II, breast cancer was referred to the CORE program following partial mastectomy and reconstruction with removal of axillary lymph nodes. Serial cardiopulmonary exercise testing (CPET) was performed at program entry, mid-chemotherapy (14 weeks), post-chemotherapy/pre-radiation (25 weeks), and post-radiation (32 weeks) to assess changes in cardiorespiratory fitness. Individualized exercise programming was provided and included 60-minutes of aerobic (AERO) and resistance training (RT). RT was performed twice weekly and included 2-3 sets of 8-12 repetitions using machines targeting the major muscle groups. AERO consisted of twice weekly in-person training at a target HR range of 60-85% of HR Reserve for 30 to 45 minutes using various exercise modalities. The patient was encouraged to perform aerobic exercise at home whenever feeling able. Chemotherapy and radiation treatment was carried out during the CORE program and the phases of treatment indicated the timing of CPET. RESULTS: Peak oxygen uptake (VO2peak) was 30.0 ml·kg-1·min-1 at program entry, 23.8 ml·kg-1·min-1 at mid-chemotherapy, 31.2 ml·kg-1·min-1 at post-chemotherapy/pre-radiation, and 25.7 ml·kg-1·min-1 at post-radiation. The ventilatory anaerobic threshold (VAT) was determined to be 14.0 ml·kg-1·min-1 at program entry, 14.0 ml·kg-1·min-1 at mid-chemotherapy, 11.4 ml·kg-1·min-1 at post-chemotherapy/pre-radiation, and 12.5 ml·kg-1·min-1 at post-radiation. Peak power output (PPO) was 148 W at program entry, 142 W mid-chemotherapy, 129 W post-chemotherapy/pre-radiation, and 139 W post-radiation. CONCLUSION: VO2peak, VAT, and PPO were affected by the various phases of breast cancer treatment despite concurrent regular aerobic activity. There remained a deficit in VO2peak and PPO following radiation treatment, but it is anticipated that these deficits will no longer exist at the 6-month post-radiation testing time point.