Achieving equity in genomic testing for breast cancer through partner-led strategies and policies.

11027 Background: Genomic testing is recommended for individuals with estrogen/progesterone receptor-positive, HER2-negative early-stage breast cancer to determine the need for chemotherapy alongside endocrine therapy. However, access disparities persist by race, ethnicity, and income. This study aims to identify modifiable barriers and co-design policy recommendations for equitable genomic testing for low-income, and racial and ethnic minoritized people with breast cancer in Northern California. Methods: Using community-based participatory research and expert panel methods, we collaborated with an 18-member expert panel of patients, caregivers, oncology clinicians, community organizations, advocates, and policymakers to identify modifiable barriers and propose solutions. Phase 1 involved an 85-question survey and semi-structured interviews with patients, caregivers, clinicians, navigators, policymakers, and payers, administered by bilingual community health workers in Spanish, Tagalog, and Chinese, to assess genomic testing barriers and solutions. Phase 2 used Delphi consensus methods with the expert panel to finalize policy recommendations. Results: Of 912 invited, 831 participated in surveys (90% response rate), and all 30 purposively sampled individuals participated in interviews (100% response rate). Survey participants included 514 patients, 101 caregivers, 94 clinicians, 74 navigators, 25 policymakers, and 23 payers. Among patients, 102 (19.8%) were Asian, 132 (25.7%) Black, 138 (26.9%) Hispanic White, 28 (5.5%) Non-Hispanic White, and the remainder preferred not to answer. Racial and ethnic minoritized patients had significantly lower odds of genomic testing compared to Non-Hispanic Whites: Black patients 86% lower (OR: 0.15; 95% CI: 0.07-0.31), Asian patients 71% lower (OR: 0.29; 95% CI: 0.14-0.59), and Hispanic White patients 79% lower (OR: 0.21; 95% CI: 0.11-0.43). Four themes emerged from interviews: 1) limited awareness/resources, 2) inequitable care, 3) financial/cultural barriers, and 4) insufficient social support. The expert panel reached consensus on policy recommendations, including mandating reflexive, fully reimbursed genomic testing (mean rating ± SD: 8.3 ± 0.9), eliminating prior authorization (8.2 ± 0.8), removing co-pays/out-of-pocket costs (8.1 ± 0.8), and providing educational materials in preferred languages with lay terminology (7.9 ± 1.2). Conclusions: Disparities in genomic testing persist, highlighting the need for targeted interventions. Policy recommendations co-designed with communities and other interested groups can be implemented to improve equitable care.