Cascade Chatbot: A Scalable Approach to Family-Based Genetic Testing for Hereditary Cancer Syndromes.

Abstract

Cascade genetic testing enables identification of relatives at risk of hereditary cancer syndromes, creating opportunities for early detection and prevention. However, uptake of cascade testing remains low, with approximately one-third of eligible relatives completing testing, largely because of reliance on patient-mediated communication. Although clinician-mediated outreach has demonstrated improved efficacy, it is often limited by resource demands. Scalable digital health tools are a promising strategy to address this gap in testing uptake. In this quality improvement initiative, we developed a digital cascade chatbot to deliver gene-specific education and facilitate access to genetic services among at-risk relatives. Between October 2024 and January 2025, 100 consecutive probands with a hereditary cancer pathogenic variant seen in a gynecologic oncology clinic were offered a cascade chatbot to share with their relatives. The primary outcome was proband acceptance of the cascade chatbot. Secondary outcomes included sharing of the cascade chatbot with at-risk relatives and relatives' subsequent utilization of genetic services. Outcomes were evaluated through telephone follow-up at 2 weeks and 3 months after chatbot introduction. Fifty-nine of 100 probands reported having relatives who had not undergone genetic testing. Among this group, 58 (98.3%) accepted the cascade chatbot. At 2-week follow-up, 44 of 58 probands (75.9%) had shared the cascade chatbot with at least one relative, and an additional eight (13.8%) reported plans to share. At 3-month follow-up with probands, 48 (82.8%) probands had shared the cascade chatbot with at least one relative. A total of 122 relatives received the cascade chatbot and 96 (78.7%) were reached for 3-month follow-up. Among the 96 relatives reached, 49 (51.0%) had scheduled or completed a genetics appointment, and of them, 36 (73.5%) had completed testing. A cascade chatbot was highly acceptable to probands and effectively engaged relatives. Scalable digital health tools may enhance cascade testing and support precision cancer prevention.