Cluster randomised trial to evaluate the clinical benefits of decision support interventions for older women with operable breast cancer

Introduction: Breast cancer (BC) survival in older women is inferior to younger women partly due to reduced rates of surgery, chemotherapy and radiotherapy. Some treatment variance may be appropriate to minimise complications in the least fit older women, but there are no guidelines to aid decision-making regarding the level of fitness where such tailored approaches are appropriate. This cluster-randomised controlled trial (cRCT) has evaluated the impact of two decision support tools (DESIs) in older women with BC. One supports decisions about surgery (+ adjuvant endocrine therapy) or primary endocrine therapy (PET); the second concerns choosing adjuvant chemotherapy or not. Both DESIs allow treatment tailoring for fitness & frailty, based on validated outcome models derived from UK registry data. The two DESIs each have an on-line tool with down-loadable outcome print-outs, booklets & brief decision aids to support fitness tailored decision-making in older women between surgery or PET or, in the post-surgical setting, between chemotherapy or no chemotherapy. The aims were to compare quality of life (QoL) & a range of secondary outcomes including measures of decision quality & treatment choice between clusters. Methods: A multicentre cluster RCT comparing use of two DESIs versus usual care in treatment decision-making in older women (=70 years) with operable BC. Breast units (clusters) were randomised to usual care (UC) or access to both DESI interventions. The primary outcome was QoL (EORTC C30 tool). Secondary outcomes included decision quality measures, patient knowledge levels and treatment choices. Results: The study recruited 1339 women across 46 sites, (21 intervention, 25 UC), median age 77 (range 70–102 years), (670 intervention, 669 UC). There was no difference in global QoL at 6 months post-baseline on intention to treat (ITT) analysis [difference = -0.20, 95% CI -2.69 to 2.29, p = 0.90). Treatment choices were altered with 21% (123/591) of patients with an ER+ tumour undergoing PET at intervention sites compared with 15% (88/570) at UC sites (difference = 5.5%, 95% CI 1.1% to 10.0%, p = 0.02). Uptake of adjuvant chemotherapy was lower among intervention sites than UC sites 10% (64/647) v 16% (103/642); difference = -6.2%, 95% CI -10.0% to -2.5%, p = 0.001). Patient knowledge about treatments was greater in the intervention arm, with 94% vs 74% aware of treatment options (p = 0.003) & with greater awareness of treatment risks & benefits (91% vs 79%, p = 0.054). Feedback about the value & implementation of the DESIs, from patients and clinicians, was favorable. Interpretation: Use of older age specific BC DESIs increases knowledge of treatment options to facilitate shared decision-making. Their use alters treatment selection & enhances patient knowledge. Longer term follow-up is required to establish if survival outcomes are affected.