Abstract PS3-05-22: Real-world adherence to germline genetic testing guidelines in breast cancer: patterns and disparities in a community oncology setting

Abstract Objectives: Germline genetic testing is a critical component of personalized care in breast cancer, informing surveillance, treatment, and risk-reduction strategies for patients and their families. National Comprehensive Cancer Network (NCCN) recommend testing patients with early breast cancer and specific high-risk features. However, adherence to these guidelines in real-world community settings, and the role of social determinants such as insurance and geography, remains incompletely understood. Methods: We retrospectively reviewed charts of patients who were diagnosed with breast cancer at Sentara Norfolk General Hospital between June 1, 2019 to June 1, 2024. The sample included 89 patients, between 36 to 65 years old (M = 55. 53), with 88 female patients and 1 male patient. Patients were deemed eligible for genetic screening in accordance NCCN Guidelines Version 1. 2025, which included: 1) diagnosis of breast cancer at 50 years old, or 2) triple-negative breast cancer, multiple primary breast cancers, or male breast cancer, or 3) a family history of one or more close blood relative with breast cancer at or before age 50, pancreatic cancer, male breast cancer, ovarian cancer, prostate cancer with high-risk features, or three or greater breast and/or prostate cancer diagnoses on the same side of the family 1. Demographic variables included race, marital status, insurance, and social vulnerability, which was derived from zip code. Results: Genetic testing was ordered for 75% of patients (n=67). Of the total sample, 65 out of 89 patients had testing completed. Fisher’s exact tests explored relationships between social determinants and testing. For eligible patients, no significant relationships were found. However, examination of subgroup testing completion rates showed some group differences. Nearly 92% of White eligible patients received testing, compared to 77% of Black eligible patients. Married patients completed testing at a rate of almost 87%, while 70% of single people completed testing. Additionally, ninety-two percent of eligible patients with a qualifying family history were tested, compared to 83% based on age and 80% based on cancer type. Discussion: Despite high overall adherence to NCCN guidelines for germline genetic testing in this community-based breast cancer cohort, disparities emerged across several social dimensions. While statistical significance was not reached, subgroup analyses revealed meaningful trends. Black patients were less likely to complete testing compared to White patients, highlighting potential racial disparities in access, communication, or trust. Similarly, single patients had lower testing completion rates than married patients, suggesting that social support may influence engagement with genetic services. Overall, these findings suggest that even in a high-performing clinical setting, social determinants of health may influence the delivery of precision oncology, and targeted interventions are needed to ensure equitable access to genetic testing for all eligible patients. References: - 1 National Comprehensive Cancer Network. Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic. Version 1. 2025. https: //www. nccn. org/professionals/physiciangls/pdf/geneticsbop. pdf. Citation Format: L. Shahid, A. J. Patev, M. A. Danso, R. A. Burke, N. Balanchivadze. Real-world adherence to germline genetic testing guidelines in breast cancer: patterns and disparities in a community oncology setting abstract. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32 (4 Suppl): Abstract nr PS3-05-22.