24-week home-based walking program in the early adjuvant setting in breast cancer patients who receive aromatase inhibitor endocrine therapy: lessons learned from the SAKK 95/17 WISE prospective, randomized, multicenter trial

BACKGROUND: Aromatase inhibitor (AI) induced arthralgia/myalgia (AIA) is a frequent side-effect of adjuvant breast cancer (BC) endocrine therapy. We investigated the effect of a user-friendly activity tracker to accompany a 24-week walking program, from the start of adjuvant AI-therapy, on patient AIA symptom burden and medication adherence. METHODS: 320 early-stage BC patients were included and randomly allocated to the intervention (arm A, n = 158) or control arm (arm B, n = 162). The intervention in arm A was aimed at briskly walking outdoors for 30 min continuously with 100 steps/minute for 5 days a week, versus an unspecified recommendation of physical activity (PA) in arm B. The patients wore an activity tracker with a customized display. RESULTS: The intervention compliance in arm A was high, 94% of patients completed the 24-week intervention phase and 68% reached the recommended intervention PA goal. Median daily number of steps was higher in arm A (8542 vs. 7742; p = 0.015). At the end of the intervention phase, activity levels were higher in the intervention group (79.1% vs. 72.8%). These higher values remained unchanged in the follow-up phase at 12 months (79.1% vs. 69.8%) and at 24 months (69.6% vs. 61.1%). Neither the high incidence of AIA during the intervention phase (A:58.2% vs. B:56.2%) nor the reported pain levels differed between the trial arms. CONCLUSION: BC patients are highly motivated to pursue new approaches for health promotion in addition to oncological therapies. Activity trackers with training instructional guidance are useful for maintaining training levels achieved over a longer period of time.