Pilot implementation study of a default genetic referral process for patients with early-onset colorectal cancer

Early-onset colorectal cancer (CRC) diagnosed under age 50 is increasing at alarming rates, with >75% of early-onset cases occurring in patients between 40 and 49 years old. Germline genetic risk evaluations are key to delivering high-quality care to these patients. We conducted a single-arm pilot implementation study of a default genetic referral process for patients diagnosed with CRC between ages 40 and 49 at 5 hospitals in an academic health system. A research coordinator notified patients and their oncologists of their eligibility for a default genetic referral, after which all patients who did not opt out were referred for genetic counseling, testing, and result disclosure as per usual care. The primary outcome was the genetic referral rate; secondary outcomes included the percentage of eligible patients who were scheduled for a genetic evaluation, completed genetic counseling, and underwent testing within 3 months of the initial referral. We conducted semistructured exit interviews with a subset of patients and oncologists to elicit feedback on the intervention. We included 53 patients, of whom 49 (92%) were referred to genetics, 38 (72%) were scheduled, 22 (42%) completed genetic counseling, and 13 (25%) underwent testing within 3 months of the initial referral. In exit interviews (n = 10 patients and 10 oncologists), participants reported finding the default genetic referral process acceptable and feasible to implement. A default genetic referral process is acceptable, feasible, and associated with a high referral rate for patients with early-onset CRC; however, subsequent scheduling, evaluation, and testing rates remain suboptimal.