Study design
breast cancer
RECRUITMENT, BREAST CANCER
The present study (PROCAS-2) employed a non-randomised controlled trial of the effects of offering women either standard NHSBSP mammography screening or BC-Predict alongside the NHSBSP offer of mammography screening. BC-Predict involved obtaining breast cancer risk information from women to input into the computer model Tyrer-Cuzick (v8), incorporating an automatic measure of breast density (and in a small proportion a polygenic risk score from saliva DNA) to generate 10-year breast cancer risks for feedback. NHS ethical approval for the PROCAS-2 study was granted by Harrow Research Ethics Committee (ref 18/LO/0649)/IRAS-project ID:239199, and it was included in the ISRCTN registry, with fuller study details included in a study protocol paper [Nested within the BC-Predict intervention arm was a further adaptive non-randomised factor, whereby various changes were made to methods of recruitment including changes to the information sheets and invitation letters and variations in uptake rates were noted (Supplementary Table After a pilot phase, BC-Predict started in September 2019 in two Greater Manchester sites (Trafford and Withington Community) Phase 1. The intended start was delayed in the two East Cheshire sites (Supplementary Table Therefore, recruitment did not finish in the first two sites until September 2, 2020. The switch over (Phase 2) to Oldham in Greater Manchester, The East Cheshire sites and the two North-East Lancashire sites occurred on the 3 September, 15 September 2020 and 2 February 2021, respectively. The study was extended to July 9, 2021 at all Phase 2 sites to adjust for the reduced invitation rates for screening.