Identifying breast cancer diagnosis stages in high-risk patients using a population genetic screening program at a community health system.

e22521 Background: Endeavor Health implemented a family-health-history screening tool called the Genetic Wellness Assessment (GWA) in routine primary care annual visits to improve access to inherited cancer risk assessment, prevention, and tailored treatment strategies through population-based genetic testing (PBGT). Our study aimed to assess the clinical stages of breast cancer (BC) diagnosis in patients who were identified as high-risk for inherited cancer on the GWA, received PBGT, and were diagnosed with BC post completion of the PBGT. Methods: Data was extracted from the electronic health record and the internal Endeavor Health cancer registry (CR) to identify patients who were screened as high-risk for inherited cancer using the GWA, underwent PBGT, and were subsequently diagnosed with BC between 2018 and 2024 (GWA patients). The stages of BC diagnosis in these patients were compared to the larger BC patient population in the internal CR during the same timeframe. Stage of breast cancer was defined as ductal carcinoma in situ (DCIS), localized (confined to primary site), regional (spread to regional lymph nodes), and distant (cancer has metastasized). Descriptive statistics was used for data analysis. Results: Thirty-three GWA patients were diagnosed with BC. Nine (27%) with DCIS, 22 (67%) with localized disease, and 2 (6%) with regional disease. Four (12%) of these patients had a pathogenic variant in a BC risk gene (2 BRCA2 , 1 CHEK2 , and 1 TP53 ). During this same time period, 1447 patients were available in CR data, for which the stage breakdown at diagnosis was: DCIS 268 (19%), 1045 (72%) localized, 115 (8%) regional, and 19 (1%) distant. Conclusions: A higher proportion of the general Endeavor Health BC population had regional or distant disease compared to the GWA population. Notably, nearly one third of GWA patients were diagnosed with DCIS and there were no cases of newly diagnosed metastatic BC in this population. Further research is warranted to understand how GWA participation may influence patient screening and prevention practices and result in earlier BC diagnosis. Breast cancer diagnosis stages in GWA patients and endeavor health cancer registry patients from 2018 to 2024. BC Diagnosis Stages in GWA Patients BC Diagnosis Stages in Cancer Registry Patients Count Percentage Count Percentage DCIS 9 27% 268 19% Localized 22 67% 1045 72% Regional 2 6% 115 8% Distant 0 0% 19 1% Total 33 1447