Abstract Background: The high-level aims of the Advocate-BREAST study are to study and improve the overall experience of patients with breast cancer (BC) through education, shared decision making, and patient-centered clinical trials. Assessing areas of unmet need in care delivery and research as identified by patients with BC will direct future research and help us improve the patient experience. Methods: In April 2022, an electronic RedCap survey was circulated to 6,918 BC survivors (stage 0-4 disease) enrolled in the prospectively consented Mayo Clinic Breast Disease Registry (MCBDR), which includes rural-dwelling women often underrepresented in cancer care delivery research. The questionnaire asked about satisfaction with multiple aspects of cancer care delivery and the education and support patients receive(d) regarding practical, financial, emotional, societal and spiritual concerns linked to BC. Patients were also asked to rank potential Quality Improvement (QI) projects in order of the likelihood the proposal could improve quality of life for BC patients and their families. Questions regarding clinical trial participation, use of integrative medicine and perspectives on medical second opinions were also included. Responses were collected via anonymous local language questionnaires. Results: The survey received 2,451 responses from MCBDR enrollees. 13% of respondents had Ductal Carcinoma in Situ (DCIS), 83% had early breast cancer (EBC) (Stage 1-3) and 4% had metastatic breast cancer (MBC). Mean age was 64 (SD 11.9), and mean time in months since diagnosis was 93 (SD 1.42). 69.3 % of patients received all care at Mayo Clinic; 24.7% at Mayo and another healthcare organization, and 6% at a non-Mayo site. Although the overall experience of care was generally good/excellent (> 90 %), gaps were perceived in terms of information provision, continuity of care (including survivorship care after 5 years), navigating care transitions, and timely access to mental health resources. The main severe symptoms patients recalled in year 1 were hair loss, eyebrow/eyelash thinning, hot flashes, sexual dysfunction and cognitive issues. The main concerns patients recalled in the first year following diagnosis were fear of BC recurrence and spread as well as of dying, practical and emotional concerns for family members if they were to die of BC, and their emotional health. Patients were most dissatisfied with information and support related to management of lymphedema, sexual dysfunction, eyebrow/eyelash thinning, and peripheral neuropathy. Respondents overwhelmingly voiced the need for the following QI projects: i) lifetime access to online patient educational resources: including summary “cheat sheets”; ii) educational, practical, emotional and holistic support programs for MBC patients, and iii) BC Wellness Programs for EBC and MBC patients (endorsed by 82.6%; 82.4% and 81.9% of respondents, respectively). Predictors in terms of age, time since diagnosis, and cancer stage that may account for satisfaction with care, concerns, or QI preferences will be reported at the meeting. Of 20% of patients who saw an Integrative Medicine provider, 85% were satisfied/very satisfied with the care received. Of ~40% of patients who received a second opinion regarding their BC diagnosis and treatment plan, 96% found this beneficial. 47% of respondents had participated in a clinical trial, which is higher than seen in the general population such that conclusions may not be generalizable. Of those who had not participated in a study, 30% reported that they were unsure if they would participate in a trial if offered, and 9% reported that they would decline same. Conclusion: Understanding the lived experiences of persons with BC is essential to improve quality of care. Patients with early and advanced BC desire holistic care, continuity of care, concise educational resources and early psychological support. Citation Format: Kathryn Ruddy, Ciara C. O’Sullivan, Nicole Larson, Robert A. Vierkant, Mary Lou Smith, Cynthia Chauhan, Fergus J. Couch, Janet Olson. Advocate-BREAST: Advocates and Patients’ Advice to Enhance Breast Cancer Care Delivery, Patient Experience and Patient Centered Research by 2025 [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-05-41.