Short-term outcomes of a randomized, mixed-methods trial to improve disclosure of hereditary cancer test results and follow-up communication with family members

Purpose This mixed-methods study evaluated an online, theory-guided family communication intervention (GeneSHARE) designed to increase the initial sharing of genetic test results and follow-up communication with family members among individuals with a germline pathogenic or likely pathogenic variant (GPV) in a hereditary cancer gene. Methods This randomized trial consisted of 528 participants with a GPV who self-reported having at least 1 untested, at-risk relative, of whom a subset of these participants was randomized to the GeneSHARE intervention and received resources designed to facilitate sharing of information and ongoing communication about hereditary cancer genes. All participants were asked to complete baseline and follow-up surveys, and a subset of participants was asked to complete an interview. Quantitative analyses compared communication outcomes across study groups, and qualitative interviews with a purposive subsample ( n = 10) examined the use of the GeneSHARE intervention. Results Among the 442 participants who had not shared GPV results with all living, adult, blood-related relatives (ie, first-degree and second-degree relatives and cousins) at risk of having the GPV, initial disclosure to at least 1 relative was significantly higher in the intervention group (29.5% vs 20.8%; P = .042). More than half of all 528 participants followed up with at least 1 at-risk relative who had previously been informed of the GPV, though the rates did not differ between the groups ( P = .161). Interviews showed that study emails prompted communication, and one-page handouts facilitated sharing. However, intervention delivery long after testing, login barriers, and limited emphasis on follow-up communication tempered the intervention’s impact. Conclusion The online intervention increased initial disclosure to at-risk relatives but did not enhance follow-up communication after initial disclosure. Findings highlight the value of integrating reminders about communicating with family members into interventions, providing interventions earlier in care pathways, and expanding resources that support ongoing family communication. © 2026 The Authors.