How to support cancer genetics counselees in informing at-risk relatives? Lessons from a randomized controlled trial

Objective: In hereditary and familial cancer, counselees are requested to inform their at-risk relatives. We developed an intervention to support counselees in this task. Methods: A randomized controlled trial was conducted aimed at improving cancer genetic counselees’ i) knowledge, ii) motivation to disclose information, and ii) self-efficacy in this regard. Eligible participants were randomized to telephonic counseling (n = 148), or standard care (n = 157) and assessed at baseline, 1 week post-intervention, and 4 months after study enrolment. Results: No between-group differences were found in participants’ knowledge, motivation, and self-efficacy. Knowledge concerning which second-degree relatives to inform was lower compared to first-degree relatives. About 60% of the participants was of the opinion that they needed to inform more relatives than stated in their summary letter and only about 50% were correctly aware of which information to disclose. Of note, at baseline, almost 80% of the participants had already correctly informed their at-risk relatives. Conclusions: Since, unexpectedly, counselees already informed most of their relatives before the intervention was offered, efficacy of the intervention could not convincingly be determined. Counselees’ knowledge about whom to inform about what is suboptimal. Practice Implications: Future interventions should target a more homogeneous sample and address counselees’ understanding and recall