Abstract PO2-08-01: Universal Multi-Gene Panel Testing of Newly Diagnosed Breast Cancer Patients in a Community Healthcare System

Abstract Introduction Multi-gene panel, germline genetic testing has emerged over the last decade as a useful tool in the assessment of hereditary cancer syndromes. As barriers to genetic testing are reduced, offering universal genetic testing to all cancer patients is a practice gaining traction. We present outcomes data specific to the offering of universal, multi-gene panel testing to newly diagnosed breast cancer patients in a community hospital setting. Methods A retrospective chart review was performed for all newly diagnosed breast cancer patients (n=1005) at a community hospital between 8/5/2019 and 8/5/2022. Uptake and outcomes of genetic counseling and genetic testing were assessed. All patients were offered genetic counseling, and those who consented to genetic testing were offered a multi-gene panel (37-93 genes). The National Comprehensive Cancer Network (NCCN) Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic (2020) guidelines were utilized to distinguish which patients met traditional genetic testing criteria. Results Of all newly diagnosed breast cancer patients, 915 (91.1%) patients underwent genetic counseling and 871 (86.7%) patients elected for genetic testing. Of those who declined genetic testing (n=134), 39 (29.1%) reported previous genetic testing. Of patients tested, 489 (56.1%) met NCCN criteria. Overall, 114 (13.1%) of tested patients received results with likely pathogenic/pathogenic (LP/P) variants. Of those, 86 (75.4%) had a clinically significant variant, a high-risk, moderate-risk or another dominantly inherited gene variant, while 28 (24.6%) were identified as genetic carriers; Table 1 summarizes genes with LP/P variants in this cohort, with 10 patients receiving results for 2 variants. Of the patients with clinically significant genetic results, 58 (67.4%) met NCCN criteria. Furthermore, 65 patients (75.6%) reported a family history of cancer relevant to the identified LP/P variant. The average age of the total population, and of those with a positive result, was 62 years. While nearly 19% of all patients tested were under age 50, patients under 50 comprised only 14.0% (n=12) of patients with a clinically significant result. Breast cancer management changes, including addition of a PARP inhibitor to chemotherapy regimen and/or elected bilateral mastectomies in the setting of unilateral disease, were noted in 71.4% (n=20) of patients with high-risk genetic findings and 20.6% (n=7) of patients with moderate-risk genetic findings. Conclusion The 86.7% uptake of genetic testing suggests implementation of universal testing in a community setting is feasible and favored by patients. Clinically significant genetic results would have gone undetected in 32.6% of patients if NCCN criteria was strictly utilized to offer testing. In addition to the 62 patients with high and moderate risk genetic results, utilization of expanded panel testing provided benefit for an additional 24 patients found to have an actionable variant in a gene that would not have been detected on traditional breast cancer panels. Our data supports the offering of genetic testing to all newly diagnosed breast cancer patients, regardless of age, family history, or other criterion, to inform precise breast cancer management and overall, lifetime cancer risks. Genetic Findings of Universal Multi-Gene Panels in a Community Setting Citation Format: Natalie Johns, Jody Wallace, Darbey Raible, Jordan Brady, Grace Miller, Brooke Phillips. Universal Multi-Gene Panel Testing of Newly Diagnosed Breast Cancer Patients in a Community Healthcare System abstract. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-08-01.