202P Participant perceptions and mammography adherence from DETECT-A: The first prospective interventional trial of a multi-cancer early detection (MCED) blood test

MCED tests may improve early cancer detection, but the impact of MCED testing on anxiety and standard of care (SOC) screening adherence is unknown. The DETECT-A trial evaluated the CancerSEEK MCED test in 9,911 women without a cancer history (Science, 359:6499, 2020). DETECT-A participants without a cancer diagnosis were invited to a follow-up observational study involving annual surveys. Here we report on participant satisfaction, anxiety, intent to adhere to SOC cancer screening, and adherence to breast cancer screening. The survey, conducted approximately 3 years after DETECT-A enrollment, assessed: a) whether participants regretted DETECT-A participation or would participate again, b) how likely they were to adhere to routine cancer screenings, and c) how participation affected their anxiety. Adherence to biennial mammography screening was assessed at the month of survey completion for screening-eligible participants with evaluable medical records. Of the 7573 DETECT-A participants contacted, 3,870 (51%) completed a survey. Of the 3,788 respondents who answered all survey questions, 96.9% indicated no participation regret, 98.8% would participate again, 99.5% reported being equally or more likely to adhere to SOC screening, and 98.7% reported no change in or reduced anxiety. Of 1,053 participants eligible for mammography with available health records, 93.4% (n=984) were adherent with mammography screening. 94.3% of participants with false positive (FP) results who completed a survey (n = 35) reported no change or a reduction in anxiety; 5.7% (95%CI 1.6%-18.6%) reported an increase in anxiety compared to 1.3% (95% CI 0.9%-1.7%) of participants with true negative results (p = 0.07). A follow-up study of MCED participant survey responses revealed high levels of participant satisfaction, intent to adhere to SOC screening, and mammography adherence. Most participants reported no change or a decrease in anxiety. This data suggest that MCED testing with imaging-based diagnostic resolution does not significantly increase anxiety or negatively impact mammography adherence for most participants, including those with FP results.