After tumor removal, patients with hormone receptor positive breast cancer tumors often receive adjuvant endocrine treatment, with the use of an aromatase inhibitor (AI) being standard of care in the population of postmenopausal women. Common side effects of AI therapy are joint pain, muscle pain, stiffness, fatigue, hot flashes, and weight gain. Arthralgia and/or myalgia can result in lower physical activity and can negatively influence quality of life (QoL). In addition, muscle or joint pain/stiffness are among the main reasons for non-compliance and discontinuation of AI therapy. Because AI therapy is usually administered for 5 and sometimes even 10 years, this is a major clinical challenge.~For breast cancer patients undergoing AI therapy, physical activity can provide potential benefit by reducing muscle/joint pain and fatigue and can thus improve QoL. The preventive effect of physical activity on AI side effects, however, remains elusive. In addition, activity programs to reduce AI side effects have so far mostly been rather complex. The primary aim of the trial is to investigate if a simple outdoor walking intervention, which is practicable under real-life conditions, beginning at the start of adjuvant AI therapy, can prevent the occurrence of muscle or joint pain/stiffness in breast cancer patients.~Furthermore, this trial will assess the effect of physical activity on symptom burden in general and quality of life in patients receiving adjuvant AI therapy. During the follow-up phase, the trial will assess whether this intervention leads to a sustained change in lifestyle regarding activity, less pain, and better treatment adherence in the intervention group.
The primary aim of the trial is to investigate if a simple outdoor walking intervention, which is practicable under real-life conditions, beginning at the start of adjuvant aromatase inhibitor (AI) therapy, can prevent the occurrence of muscle or joint pain/stiffness in breast cancer patients.