Assessing the Effect of a Blood-based Colorectal Cancer Screening Test on Screening Adherence and Colonoscopy Completion

Objectives: Colonoscopy and stool-based testing are the two predominant colorectal cancer (CRC) screening tests used in the US, and both reduce colorectal cancer mortality. However, only 62% of Americans are up to date with screening, partly because many individuals find these two tests inconvenient or unacceptable for a variety of reasons. There is an unmet need for a non-invasive test that does not require bowel preparation or handling stool, and the Septin9 DNA blood test may be an alternative for those individuals who would otherwise remain unscreened. Aims: Aim 1: To measure screening uptake with a blood test in screen-resistant patients who have declined both colonoscopy and fecal immunochemical testing (FIT) at the Manhattan VA Medical Center * Sub-Aim 1a: To assess the proportion of those with a positive blood-based screening test who undergo diagnostic colonoscopy * Sub-Aim 1b: To describe the endoscopic findings on diagnostic colonoscopy Aim 2: To survey screen-resistant patients to understand their beliefs and attitudes about colorectal cancer screening and testing options We hypothesize that a substantial proportion of patients who have refused colonoscopy and FIT will accept the blood test. We hypothesize this will be driven by the convenience of the blood test. Methods: This will be randomized controlled trial of individuals who have refused colonoscopy and FIT within past 6 months. Eligible patients will be randomized 1:1 to the intervention or control group. Both groups will be invited to participate in navigated colonoscopy or FIT by letter and telephone call. The intervention group will also be invited to participate in the blood test if they refuse colonoscopy and FIT. We will enroll 180 participants in each group (total n=360).