Improved access to genetics for individuals with potential germline mutations identified on somatic testing.

339 Background: Somatic testing is increasingly common in treating cancer and may identify mutations that necessitate confirmatory germline genetic testing. Management of these results varies by institution. From 2021-2024, we completed an iterative approach to determine the most effective method for follow-up germline testing. Methods: We conducted 3 six-month sequential phases to determine the most effective approach to follow up on somatic findings concerning for germline origin. Phase I (3-9/2021), consisted of weekly e-mail notifications sent by the genetics program to the referring provider regarding patients who had somatic mutations of potential germline origin, and recommended providers refer the patient to genetics. Phase 2 (10/2021-4/2022), consisted of monthly e-mail notifications to the referring provider, clinical staff and included cancer center leadership. In phase 3 (10/2023-4/2024), GC assistants and medical secretaries facilitated referrals and direct outreach to schedule patients for germline follow-up. We measured the percentage of patients referred to genetics, who completed germline testing, and had confirmed pathogenic germline mutations. Results: In Phase I, 38% of patients were referred to genetics, 23.5% completed germline testing, and 37% had positive results (Table 1). In Phase 2, 19% of patients were referred to genetics, 4.7% completed germline testing, and 43% had positive results. In Phase 3, using the GC facilitated approach, 87.5% (70/80) of patients were referred. Those not referred had already undergone germline testing, were deceased or transferred care out of state. Of the 70 patients, 38 met with a GC and 30 elected to proceed with germline testing. There are 25 (36%) genetic test results available to date. 37% (26/70) patients did not complete a genetics appointment. 58% (15/26) could not be reached to schedule an appointment. Nine individuals declined or deferred an appointment. Five patients were deceased before a genetics appointment could be coordinated. For those that received referrals to genetics in phase 3, the germline positive results rate was 92% (23/25). Conclusions: The GC driven referral pathway was most effective at facilitating referral and completion of confirmatory testing for patients with somatic findings concerning for germline origin. Follow-up of these results shows an extremely high rate of germline positive results, making subsequent testing imperative for centers treating cancer patients. Given implications for cascade testing, future research is needed to study upfront consenting approaches to automate subsequent germline testing and notification in this population. Phase Intervention Potential Germline n, (%) Referred n , (%) Completed n , (%) Germline Positive n , (%) 1 Weekly Emails 162 62 (38%) 38 (61%) 14 (37%) 2 Monthly Emails 150 28 (19%) 7 (25%) 3 (43%) 3 GC Driven Referrals 80 70 (87.5%) 25 (36%) 23 (92%)