Alternative model to deliver germline genetic testing to patients with advanced prostate cancer (PCa).

Abstract

123 Background: Genomic testing is now standard-of-care (SOC) for PCa patients with both therapeutic and hereditable consequences. National guidelines recommend germline testing in all high-risk and advanced PCa patients, regardless of age or family history. Yet, many systemic barriers prevent patients from receiving germline testing promptly, including the burden of appointments, comorbidities, transportation, provider knowledge of genetic testing, and insufficient genetics workforce that limits timely referral to genetic counselors. Methods: We developed a streamlined, alternative genetic care delivery model to improve rates of germline genetic testing for PCa patients. A multidisciplinary team (genitourinary medical oncologists, advanced practice RN, and genetic counselors) developed a tailored pre- and posttest counseling curriculum for PCa patients undergoing germline testing that was delivered by oncology providers. Pretest counseling was incorporated into SOC counseling for somatic tumor genomic testing performed to personalize therapeutics. Systematic posttest counseling was delivered by oncology providers, and men with germline pathogenic/likely pathogenic (P/LP) variants were referred to certified genetic counselors for formal genetic counseling. We retrospectively collected data on PCa patients treated at an academic oncology practice who underwent paired germline/somatic testing through a commercial lab accompanied by tailored pre/posttest counseling, including demographics, clinical characteristics, and germline test results. We performed quarterly audits to monitor quality metrics. Results: From September 2021 to May 2023, seventy-five PCa patients underwent paired germline/somatic tumor testing. The racial/ethnically diverse patient population (self-identified) included 81% Black, 13% Hispanic, and 6% non-Hispanic White men. At the time of analysis, 64 tests had resulted; 9.4% of patients (n=6) had a P/LP germline variant, and 31.2% of patients (n=20) tested negative. The majority of patients (59.4%, n=38) had a variant of unknown significance (VUS). Additional data will be available at the time of presentation. Conclusions: Providing paired germline/somatic tumor testing with tailored pre/posttest education delivered by oncology providers, and formal genetic counseling reserved for patients with P/LP germline variants, is an efficient way to provide guideline-directed genetic services for PCa patients. Given the frequency of VUS, education for pre/posttest counseling is essential, particularly in under-represented minority populations. The frequency of actionable mutations is reduced in underrepresented minority PCa patients compared with reports in the literature, reflecting limitations of current germline testing/bioinformatics platforms and the need for greater inclusion of diverse populations in future studies.