Evaluating the effect of the SMART intervention in people with recently diagnosed breast cancer who are being treated at a public tertiary hospital in Australia: protocol and statistical analysis plan for a single-blinded, single centre randomised controlled trial

Abstract

Introduction Adults undergoing treatment for breast cancer (BC) are advised to participate in regular exercise. However, many struggle to exercise consistently due to the side effects of systemic treatments including nausea, fatigue, and pain. In adults with newly diagnosed BC, this trial will evaluate the effectiveness of a new exercise intervention, compared with usual care, on outcomes including health-related quality of life (HRQoL). Materials This randomised controlled trial is underway at an Australian tertiary hospital. The protocol was prospectively registered (Australian New Zealand Clinical Trials RegistryACTRN12623001168640p). Consenting adults with BC diagnosed within the prior six months, with planned chemotherapy and/or endocrine treatment will be randomised to an intervention or control group. Both groups receive usual physiotherapy and medical care. Those allocated to the intervention group are offered participation in the ‘SMART’ intervention (Self-determined, Monitored, Adaptable, Rehabilitation with Telehealth support). This involves 16-weeks of tailored, one-on-one physiotherapy-led exercise sessions including behaviour change techniques and the weekly goal of completing 150 minutes of aerobic exercise and two resistance training sessions. The primary outcome is HRQoL and secondary outcomes include physical assessments (muscle strength, exercise tolerance, body composition), healthcare utilisation, workplace absenteeism, mood, psychological determinants of behaviour change, chemotherapy completion rates and endocrine therapy completion. All outcomes are measured prior to randomisation and 16 weeks following randomisation. Additional assessments of all outcomes (excluding the physical assessment) occur at 8 weeks and 52 weeks following randomisation. Ongoing recruitment for two years from June 2024 is expected to achieve a sample size of 260. No results have been analysed. Discussion If the SMART intervention produces favourable change, this will support its adoption in clinical practice. A greater understanding of factors including BC stage, treatment type or variables relating to the exercise program, that influence the magnitude of exercise-induced change on HRQoL will inform future exercise programs.