Clinical Trial Evaluating the Efficacy and Implementation of an Early Adapted Physical Activity to Prevent and Manage Aromatase Inhibitor-induced Musculoskeletal Pain in Breast Cancer (APIS)

Aromatase inhibitors (AI) are the standard adjuvant hormone therapy for postmenopausal women with hormone-sensitive breast cancer. However, nearly half of patients experience AI-induced musculoskeletal symptoms (AIMSS), particularly pain, which compromise quality of life and treatment adherence. While adapted physical activity offers proven benefits in oncology, its specific role in preventing or managing AIMSS remains unclear. Moreover, the maintenance of physical activity during the care pathway in real-world settings is limited, highlighting the need for hybrid approaches that evaluate both clinical effectiveness and implementation. In response to these challenges, the primary study aim will be to compare the prevalence of musculoskeletal pain after six months of aromatase inhibitor therapy between patients initiating a personalized adapted physical activity program at the beginning of the care pathway and those receiving usual care. Secondary aims will be to (1) assess additional effects of the intervention on physical health, psychosocial well-being and treatment adherence, (2) explore contextual factors influencing program implementation in routine oncology care and (3) identify potential risk factors for the development of AIMSS. The APIS study is a hybrid type I effectiveness-implementation randomized controlled trial including 182 postmenopausal women with non-metastatic hormone-sensitive breast cancer. APIS will generate new evidence on the clinical and implementation effectiveness of early personalized APA (Adapted Physical Activity) in preventing AIMSS. The hybrid design will support the development of sustainable, patient-centered interventions, potentially improving quality of life, adherence to AI therapy and long-term outcomes in breast cancer survivorship. Ancillary study (Groupement Hospitalier Nord, Hospices Civils de Lyon) The humero-scapulo-thoracic region is particularly exposed to functional alterations during the course of care of patients treated for breast cancer. In addition to the loss of strength and mobility associated with surgical and medical treatment, the shoulder can also be the site of pain due to AIMSS or PMDS (Post-Mastectomy Pain Syndrome). These pains are often studied separately, depending on the treatment, but few studies offer a global vision of the functional evolution of the shoulder throughout the course of care, enabling prevention and adjustment of management. It is also relevant to assume that early APA treatment could improve functional rehabilitation in this area. The aim of this study is therefore to evaluate the impact of an APA assessment and early referral to a personalized program (APIS protocol) on shoulder functionality, depending on the time of intervention in the therapeutic pathway.