Informing relatives about their hereditary or familial cancer risk: study protocol for a randomized controlled trial

Background: Genetic counseling for hereditary breast or colon cancer has implications for both counselees and their relatives. Although counselees are encouraged by genetic counselors to disclose genetic cancer risk information, they do not always share this information with their at-risk relatives. Reasons for not informing relatives may be generally categorized as a lack of knowledge, motivation and/or self-efficacy. Presented here is the protocol of a randomized controlled trial that aims to establish the effectiveness of an intervention focused on supporting counselees in their disclosure of genetic cancer information to their relatives. Methods/Design: A multicenter randomized controlled trial with parallel group design will be used to compare the effects of an additional telephone counseling session performed by psychosocial workers to enhance the disclosure of genetic cancer information to at-risk relatives (intervention group) with a control group of standard care. Consecutive index patients with relatives at risk for hereditary or familial breast and/or ovarian cancer or colon cancer, are randomly assigned (block size: 8; 1:1 allocation ratio) to the intervention (n = 132) or control group (n = 132, standard care). Primary outcomes are counselees’ knowledge, motivation and self-efficacy regarding informing their relatives. Discussion: This intervention may prove important in supporting counselees to disclose hereditary and/or familial cancer risk information to at-risk relatives and may enable more at-risk relatives to make a well-informed decision regarding genetic services and/or screening. Trial registration: This trial is registered in the Netherlands National Trial Register (NTR) with trial ID number NTR3745