Supplementary Material for: Health system-led early consent and direct contact of at-risk relatives: Pilot study results

Introduction: At-risk relatives of probands with genetic variants associated with hereditary cancer risk should receive cascade genetic testing. In the U.S., probands are expected to notify their own at-risk relatives, but many relatives never learn of their risk, representing missed opportunity to reduce morbidity and mortality associated with hereditary cancers. Direct contact of relatives could reach relatives not contacted by the proband. We conducted a single-arm, prospective pilot evaluation of a direct contact intervention based on patient and family preferences. Here we report the study’s quantitative results, measured by proband and relative participation in the intervention follow-up survey. Methods: We recruited adults receiving genetic counseling for inherited cancer risk at one U.S. integrated health system. A genetic counselor offered to contact at-risk relatives. We surveyed probands and relatives at study enrollment and 6-8 weeks and evaluated administrative data to assess the program’s outreach to probands and relatives, its acceptability, and its limited efficacy. Results: We approached 148 probands before their genetic counseling appointment. 55 (37%) consented to study participation. Of these, 31 completed genetic testing, 29 of whom provided consent to contact 101 relatives. 44% (n=45) of relatives consented to be contacted by the study genetic counselor. Acceptability was high for both groups and no harms were reported. All relatives reached (n=43) received their proband’s test results, including 6 pathogenic/likely pathogenic findings. Conclusion: A direct contact program was acceptable, reached at-risk relatives and communicated proband test results. Direct contact with early consent of relatives holds promise for future research.