Early cancer diagnoses through BRCA1/2 screening of unselected adult biobank participants

Purpose: The clinical utility of screening unselected individuals for pathogenic BRCA1/2 variants has not been established. Data on cancer risk management behaviors and diagnoses of BRCA1/2-associated cancers can help inform assessments of clinical utility. Methods: Whole-exome sequences of participants in the MyCode Community Health Initiative were reviewed for pathogenic/likely pathogenic BRCA1/2 variants. Clinically confirmed variants were disclosed to patient-participants and their clinicians. We queried patient-participants' electronic health records for BRCA1/2-associated cancer diagnoses and risk management that occurred within 12 months after results disclosure, and calculated the percentage of patient-participants of eligible age who had begun risk management. Results: Thirty-seven MyCode patient-participants were unaware of their pathogenic/likely pathogenic BRCA1/2 variant, had not had a BRCA1/2-associated cancer, and had 12 months of follow-up. Of the 33 who were of an age to begin BRCA1/2-associated risk management, 26 (79%) had performed at least one such procedure. Three were diagnosed with an early-stage, BRCA1/2-associated cancer-including a stage 1C fallopian tube cancer-via these procedures. Conclusion: Screening for pathogenic BRCA1/2 variants among unselected individuals can lead to occult cancer detection shortly after disclosure. Comprehensive outcomes data generated within our learning healthcare system will aid in determining whether population-wide BRCA1/2 genomic screening programs offer clinical utility.