Retrospective genetic testing (Traceback) in women with early-onset breast cancer after revised national guidelines: a clinical implementation study

This study focused on identifying a hereditary predisposition in women previously diagnosed with early-onset breast cancer through a retrospective outreach activity (Traceback). The objectives were to evaluate the possible clinical implementation of a simplified Traceback strategy and to identify carriers of pathogenic variants among previously untested women. Three hundred and fifteen Traceback-eligible women diagnosed with breast cancer at 36–40 years in Southern Sweden between 2000 and 2019 were identified and offered an analysis of the genes ATM, BARD1, BRCA1, BRCA2, CHEK2, PALB2, RAD51C, and RAD51D through a standardized letter. Women who chose to participate were asked about their experiences through a questionnaire. The workload for the study personnel was measured and recorded. One hundred and seventy-six women underwent genetic testing and pathogenic variants were identified in 9.7