Results From the Genetic Information and Family Testing Study: A Cluster-Randomized Trial

Cascade genetic testing in families with hereditary cancer syndromes is an important strategy to reduce the burden of cancer, but testing of relatives is low. Direct engagement of relatives through cancer survivors is a promising approach to bridge this gap.

We conducted a population-based cluster-randomized clinical trial (Genetic Information and Family Testing [GIFT]) of an online, direct-to-family, cancer genetic education and communication tool including the offer of home testing to adult relatives of cancer survivors diagnosed in 2018-2019 who carried a pathogenic variant. We selected patients through SEER and surveyed them for eligibility followed by a trial invitation. Two features were randomized: assistance from a human navigator (yes, no) and testing cost (free v $50). We hypothesized that the fraction of relatives tested in a family (primary outcome) would be higher with a navigator and free testing.

Four thousand three hundred patients were surveyed and 2,285 responded (53.1%); 2,006 eligible respondents were invited (87.8%) and 414 enrolled (20.6%). Enrolled patients reported a total of 4,946 first- and second-degree relatives (mean, 12.3; standard deviation [SD], 8.6); they invited 948 relatives (19.2%) and 303 enrolled (32.0%). Most enrolled relatives ordered testing (267, 91.3%); more than double were tested in the free versus $50 arm (odds ratio [OR], 2.5 [1.6-3.9]), but the baseline fraction tested was low at 0.03 and thus the absolute increase was modest (0.04 [95% CI, 0.02 to 0.05]). We did not find evidence for increased testing in the navigation arm (OR, 1.3 [0.8-2.1]).

GIFT is a promising blueprint for online cascade genetic education and testing. Results suggest that a low-cost, population-level intervention could be deployed without a human navigator. Additional intervention strategies are needed to increase the modest invitation and testing uptake observed in this study.