Universal vs. ASCO guidelines-based germline genetic testing for newly diagnosed breast cancer patients in resource-restricted settings.

A significant subset of breast cancer cases is attributable to inherited pathogenic genetic variants. Germline genetic testing (GGT), particularly for BRCA1 and BRCA2, represents a critical tool for precision oncology, enabling individualized risk stratification and the development of tailored therapeutic strategies. Consecutive newly diagnosed breast cancer patients eligible for GGT testing according to the latest American Society of Clinical Oncology (ASCO) guidelines were enrolled. During the study period, 1,570 patients were enrolled, median age 51 (22-96) years, majority (n = 1,352, 86.1%) were Jordanian. Based on age criteria, 1,346 (85.7%) patients were eligible for testing. Another 134 (8.5%) were found eligible for testing because of other indications including personal or family history of breast and other cancers (n = 121, 7.7%), triple-negative disease (n = 9, 0.57%) and male gender (n = 4, 0.25%). In total, 1,480 (94.3%) patients were eligible for GGT as per ASCO guidelines, leaving only 90 (5.7%) patients not candidates for testing. Pathogenic/likely pathogenic variants were identified in 23 (7.8%) patients. Applying universal GGT for all newly diagnosed breast cancer patients, regardless of their age or risk factors, would slightly increase the pool of eligible patients, the burden of which can be justified given its impact on improving referral rate.