Abstract 6276: Predictors of engagement on a closed social support network for individuals with Hereditary Breast and Ovarian Cancer syndrome and Lynch syndrome.

Abstract Background: Genomic testing is increasingly used in cancer care, but patients often receive results without formal psychosocial support. Many social support platforms for patients exist, but few are embedded within genomic results portals while also focusing on providing support for populations with hereditary cancer risk. To address this, we developed a closed Social Support Network (SSN) at City of Hope integrated in a program (HOPE-Genomics) that delivers patient-friendly genomic results. This SSN was piloted with patients with pathogenic/likely pathogenic (P/LPs) variants associated with Hereditary Breast and Ovarian Cancer syndrome (HBOC) and Lynch syndrome. We examined engagement patterns and predictors of SSN use to inform future implementation of the SSN in broader populations for patients with hereditary risk for cancer. Methods: 120 patients from City of Hope were invited to use the SSN for 4-6 months. Participants completed baseline and follow-up surveys that included psychosocial indicators (e.g., social isolation and cancer fatalism) and the Feelings About genomiC Testing Results (FACToR) scale. A subset of users participated in qualitative interviews following their participation in the pilot (n=9). SSN activity (logins, posts, likes, page views) was tracked. Patients who logged in at least once were classified as users. Chi-square/Fisher’s exact tests and multivariable logistic regression were used to compare users vs. non-users across demographic and psychosocial variables. Results: 68.3% (n=82) completed the baseline survey, 50.8% (n=61) logged in at least once, and 45.0% (n=54) completed the follow-up survey. Across all participants, there were 1081 page views, 51 posts, and 82 likes. The first discussion thread topic, “Living with a Genomic Change,” had the most activity, indicating the importance of discussion thread topic placement over content. Page views peaked approximately halfway through the pilot (i.e., 3 months). Ethnicity was a significant predictor of SSN use whereby having a Hispanic/Latino identity was associated with a lower likelihood of being a user relative to not having a Hispanic/Latino identity (OR=0.40; 95% CI=0.16-0.99; p=.047). In interviews, all participants recommended the use of the platform to others with similar P/LPs, however, most participants described useability issues such as difficulty sub-commenting and navigation obstacles on smartphones (vs. desktops or laptops) Conclusion: A closed SSN integrated in a genomic results portal achieved moderate uptake and engagement. Thread visibility drove activity. The ethnicity gap in user status indicates a need to understand decreased uptake among Hispanic/Latino participants in future research. Qualitative interviews highlighted needs for smartphone optimization, sub-commenting, and private messaging capabilities. Citation Format: Patrick Boyd, Yi Xiao, Sandra Davey, Jenna R. Hoopes, Cassiel Suarez, Justin Martinez, Alex Capasso, Kathryn Reyes, Ilana Solomon, Stacy W. Gray, . Predictors of engagement on a closed social support network for individuals with Hereditary Breast and Ovarian Cancer syndrome and Lynch syndrome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 6276.