Evaluation of decision support interventions for older women with operable breast cancer: protocol for a cluster randomised controlled trial

Introduction - Whilst breast cancer outcomes are improving steadily in younger women due to advances in screening and improved therapies, there has been little change in outcomes among the older age group. It is inevitable that co-morbidities/frailty rates are higher, which may increase the risks of some breast cancer treatments such as surgery and chemotherapy, many older women are healthy and may benefit from their use. Adjusting treatment regimens appropriately for age/co-morbidity/frailty is variable and largely non-evidence based, specifically with regard to rates of surgery for operable oestrogen receptor (ER) positive disease and rates of chemotherapy for high-risk disease. Methods and analysis - This multi-centre, parallel group, pragmatic cluster randomised controlled trial (2015-18) reported here, is nested within a larger ongoing “Age Gap Cohort Study” (2012-18; RP-PG-1209-10071), aims to evaluate the effectiveness of a complex intervention of decision support interventions (DESIs) to assist in the treatment decision-making for early breast cancer in older women. The interventions include two patient decision aids (PtDAs) (primary endocrine therapy versus surgery/AET and chemotherapy versus no chemotherapy) and a clinical treatment outcomes algorithm for clinicians. The primary outcome will be quality of life measured by EORTC QLQ C30. Randomisation is at breast unit level (53 UK sites), stratified by high/ low primary endocrine therapy and chemotherapy rates. Women (n=1500) over 70 years with primary operable breast cancer will be recruited and followed up 6 weeks to 2 years post diagnosis with longer term cancer outcomes (overall survival, disease free survival) derived from cancer registry returns. Control arm: no change to usual practice. Intervention arm: usual practice plus DESIs adopted as standard care by clinicians. ETHICS AND DISSEMINATION - National and local ethics committee approval were obtained for all UK participating sites. Results from the trial will be submitted for publication in international peer reviewed scientific journals.