North of England Women's Diet and ActivitY - After Breast Cancer (NEWDAY-ABC) intervention in women diagnosed with early oestrogen-positive, HER2-negative breast cancer: a randomised controlled feasibility study.

Background: Excess body weight is associated with higher breast cancer mortality rate. This study assessed the feasibility of a co-designed weight loss intervention (NEWDAY-ABC) versus standard care in early-stage oestrogen receptor-positive, human epidermal growth factor receptor 2-negative breast cancer patients.

Methods: This was a two-arm, parallel group, randomised controlled feasibility study. Twenty-one ER + ve, HER2-ve stages I-III breast cancer patients, within 3 years of completing primary treatment (excluding endocrine therapy), were recruited from two UK National Health Service Breast Care Units and randomised (2:1) to intervention plus standard care or standard care alone. The intervention was co-designed with patients and comprised small group-based Support & Skills workshops delivered remotely via teleconference by trained lifestyle advisors and dieticians. Feasibility outcomes included recruitment rate, data quality, intervention acceptability and adherence. Exploratory clinical outcomes included weight loss, anthropometric measures, dietary change, physical activity and patient-reported outcomes.

Results: Twenty-one women consented to the study, and 1 withdrew prior to randomisation, leaving 13 in the intervention group and 7 standard care controls, with 11 participants being followed up for 6 months. The overall attendance rate for intervention sessions was 79.6% (74/93 sessions completed). Body weight (candidate primary outcome for a fully powered randomised controlled trial) was reduced in the intervention group by 3.3 kg from baseline to 6 months, versus a 1.1 kg loss of body weight in the standard care control group. Furthermore, the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC-QLQ30) breast module symptom scale scores for breast and arm symptoms improved in the intervention arm only, accompanied by positive changes in physical activity and dietary behaviours.

Conclusion: The NEWDAY-ABC intervention is feasible and showed preliminary evidence of efficacy in terms of weight loss and other important health outcomes in women with early-stage breast cancer. The clinical and cost-effectiveness of the intervention versus standard care now needs to be robustly evaluated via an adequately powered clinical trial.

Trial registration number: ISRCTN15088551, registered 3 February 2020.