Feasibility Study of ABC for Women Treated for Breast Cancer

The investigators aim to assess the feasibility and acceptability of conducting a randomised controlled trial (RCT) to test whether receiving ABC (an online-delivered, Cognitive Behavioural Therapy \[CBT\], group-based, body image programme) alongside a psychoeducational body image booklet provides greater benefits to women treated for breast cancer compared to a receiving a psychoeducational body image booklet alone. Results from this feasibility study will inform the design, management, and future delivery of a definitive randomised controlled trial to assess effectiveness and cost-effectiveness of ABC. Specific objectives are to: * Establish appropriate, inclusive, and acceptable methods of participant recruitment, retention, and management procedures. * Establish the feasibility and acceptability of quantitative data collection, including determining appropriate primary and secondary outcome measures. * Adapt and test a measure of health and social care service use, to inform a future economic evaluation. * Establish intervention adherence and acceptability (of online setting) among participants and ABC facilitators. Participants will be randomised to either the intervention or control arm. The control arm will receive the Macmillan Cancer Support psychoeducational body image booklet. The intervention arm will receive the Macmillan booklet and the ABC programme, a 7-session, CBT group-based programme delivered online. All participants will complete self-report validated outcome measures at weeks 1 (T1; baseline/pre-intervention), 9 (T2; immediate post-intervention), 20 (T3; three-month post intervention), and 32 (T4; six-month post intervention). Following drop-out or completion of all study procedures, a subset of participants will be invited to take part in interviews.