Testing a breast cancer prevention and a multiple disease prevention weight loss programme amongst women within the UK NHS breast screening programme-a randomised feasibility study

Background: Excess weight and unhealthy behaviours (e.g. sedentariness, high alcohol) are common amongst women including those attending breast screening. These factors increase the risk of breast cancer and other diseases. We tested the feasibility and acceptability of a weight loss/behaviour change programme framed to reduce breast cancer risk (breast cancer prevention programme, BCPP) compared to one framed to reduce risk of breast cancer, cardiovascular disease (CVD) and diabetes (T2D) (multiple disease prevention programme, MDPP). Methods: Women aged 47-73 years with overweight or obesity (n = 1356) in the NHS Breast Screening Programme (NHSBSP) were randomised 0:2) to be invited to join a BCPP or a MDPP. The BCPP included personalised information on breast cancer risk and a web and phone weight loss/behaviour change intervention. The MDPP also included an NHS Health Check (lipids, blood pressure, HbA1c and personalised feedback for risk of CVD [QRISK2] and T2D [QDiabetes and HbA1c]). Primary outcomes were uptake and retention and other feasibility outcomes which include intervention fidelity and prevalence of high CVD and T2D risk. Secondary outcomes included change in weight. Results: The BCPP and MDPP had comparable rates of uptake: 45/508 (9%) vs. 81/848 (10%) and 12-month retention; 33/45 (73%) vs. 53/81 (65%). Both programmes had a high fidelity of delivery with receipt of mean (95% CI) 90 (88-98% of scheduled calls, 91 (86-95%) of scheduled e-mails and 89 (76-102) website entries per woman over the 12-month period. The MDPP identified 15% of women with a previously unknown 10-year CVD QRISK2 of >= 10% and 56% with 10-year Qdiabetes risk of >= 10%. Both groups experienced good comparable weight loss: BCPP 26/45 (58%) and MDPP 46/81 (57%) with greater than 5% weight loss at 12 months using baseline observation carried forward imputation. Conclusions: Both programmes appeared feasible. The MDPP identified previously unknown CVD and T2D risk factors but does not appear to increase engagement with behaviour change beyond a standard BCPP amongst women attending breast screening. A future definitive effectiveness trial of BCPP is supported by acceptable uptake and retention, and good weight loss.