Cascade Genetic Risk Education and Testing in Families With Hereditary Cancer Syndromes: A Pilot Study

Cascade genetic risk evaluation in families with hereditary cancer can reduce the burden of disease but the rate of germline genetic testing in relatives of patients at risk is low.

We identified all 277 women diagnosed with breast cancer in Georgia in 2017 who linked to a clinically actionable germline pathogenic variant through a Surveillance, Epidemiology, and End Results registry-variant linkage initiative. We surveyed them, and then invited eligible respondents to an online platform hosted by a navigator that offered cancer genetic risk education and germline genetic testing to untested relatives. We randomly assigned patient-family clusters at the time of the patient enrollment offer to free versus $50 (USD) test cost. Patients invited relatives to join the study through personalized e-mail. Enrolled relatives received online cancer genetic education and the opportunity to order clinical germline genetic testing through the platform. The primary outcome was the number of relatives who ordered genetic testing.

One hundred twenty-five of 277 patients completed surveys (45.2%). Most respondents were eligible for the trial offer (113 of 125; 90.4%). In the free testing arm, 20 of 56 eligible patients participated (35.7% of eligible respondents) and they invited 28 relatives: 12 relatives enrolled and 10 ordered testing. In the $50 (USD) arm, 16 of 57 eligible patients participated (28.1%) and they invited 38 relatives: 18 relatives enrolled and 17 ordered testing.

Cascade genetic testing in families with hereditary cancer syndromes accrued through a population-based cancer registry can be achieved through an online platform that offers genetic risk education and low-cost testing to relatives. A modest charge did not appear to influence the percentage of participating patients, numbers of participating relatives, and numbers of relatives who received genetic testing.