Enhancing cognitive function in breast cancer survivors through community-based aerobic exercise training: protocol for a Hybrid Type I effectiveness-implementation study employing a randomised controlled design.

Introduction: Despite growing evidence to characterise cancer-associated cognitive decline (CACD) in women with breast cancer, interventions to mitigate CACD are limited. Emerging evidence suggests aerobic exercise may enhance cognition after breast cancer diagnosis and treatment; yet, CACD remains an understudied outcome of exercise, and few high-quality studies have been conducted. In addition to knowledge gaps in effectiveness, the translation of exercise interventions to community settings remains challenging. The reast cancer easoning and ctivity tervention (BRAIN) investigates the effectiveness of aerobic exercise training, delivered in a community-based setting, for improving cognitive function in women with breast cancer and gathers information on the implementation success of the intervention.

Methods And Analysis: This Hybrid Type I effectiveness-implementation study is conducted at an academic medical centre in the southwestern United States in partnership with a non-profit, community health and wellness organisation. The study enrols 160 women diagnosed with stage I-IIIa breast cancer and within 3-36 months of treatment completion into a 1:1 randomised controlled trial. Individuals randomised to the exercise group receive a 6-month, individually tailored aerobic exercise programme delivered by exercise trainers employed at local community fitness centres. The programme is progressive in nature and designed to help participants achieve aerobic exercise levels consistent with guidelines for cancer survivors. Individuals randomise to the control group receive a 6-month health education control intervention delivered virtually by hospital-based health educators. Cognitive performance (primary), self-reported cognition, patient-reported outcomes, physical activity and cardiorespiratory fitness are measured at baseline, 6 months (postintervention) and 12 months (follow-up). Brain structure and function are measured via magnetic resonance imaging (MRI) at baseline and 6 months. Implementation outcomes are defined by the RE-AIM framework, which includes reach, effectiveness, adoption, implementation and maintenance. RE-AIM outcomes are measured at baseline, 6 months, 12 months and ongoing during the study.

Ethics And Dissemination: This study was approved by the Mayo Clinic Institutional Review Board (#23-000020). All participants provide informed consent prior to participation. Findings will be disseminated to scientific, clinical and community audiences through manuscripts, presentations and newsletters.

Trial Registration Number: NCT04816006.