Correlates of patient enrollment in a population-based randomized controlled trial of cascade genetic testing in families with hereditary cancer susceptibility.

10528 Background: Clinical trials that enroll patients through virtual approaches are growing but there is little information about the impact on access. The Genetic Information and Family Testing (GIFT) study was a population-based cluster RCT that evaluated an online platform that delivered cancer genetic education and home germline testing to families with hereditary cancer susceptibility. We examined correlates of patient enrollment to address potential barriers to trial access. Methods: We identified a random sample of adult patients with any cancer type diagnosed in Georgia or California in 2018-19 who linked to a pathogenic variant (PV) in a cancer susceptibility gene through a SEER-based data infrastructure. We initiated a mailed survey four years after diagnosis. We invited all respondents who recalled a PV on testing to enroll online in GIFT. Enrolled patients could invite their first- and second-degree relatives to enroll through the online platform. The primary endpoint was the proportion of relatives who received testing through the platform. We examined clinical and sociodemographic correlates of patient enrollment. Results: 4,300 patients were selected and 2,285 completed the survey (53.1%); 2,006 of 2,285 respondents were eligible and invited to GIFT (87.8) and 412 enrolled (20.5). The Table shows clinical and sociodemographic correlates of patient enrollment for the 1,994 with complete data. There were no substantial differences in enrollment by PV grouping, cancer type, sex, or race/ethnic groups. Enrollment was lower in older patients, those with lower education levels, and those living in census tracts with higher poverty levels. Conclusions: GIFT successfully enrolled a diverse patient population through a virtual approach. Moderate sociodemographic gradients observed in GIFT motivate strategies to ensure access to clinical trials that use virtual approaches to patient enrollment. Trial Registration: NCT05552664 at clinicaltrials.gov. Patients Enrolled n % p Gene Type with PV 0.601 BRCA1/2 or other breast cancer-related 1,650 22 Lynch Syndrome or other gastrointestinal (GI)-related 225 23 Cancer type 0.702 GI 145 20 Ovary/uterine 86 23 Female breast 1,234 22 Prostate 72 24 Other 407 19 Sex 0.594 Male 222 20 Female 1,722 22 Age <.001 <45 501 27 45-64 1,025 22 65+ 414 15