DOI: 10.6084/m9.figshare.30499902.v1
title: Embedding genetic testing in the metastatic prostate cancer pathway: understanding patient and physician perspectives

description: To understand how genetic (homologous recombination repair [HRR], including BReast CAncer [BRCA]) testing is being embedded in clinical practice and identify testing challenges given global approvals of poly(adenosine diphosphate-ribose) polymerase inhibitors (PARPis) for metastatic prostate cancer (mPCa). Data from two Adelphi Real World Prostate Cancer Disease Specific Programmes™ (DSPs; 2020 and 11/2022–7/2023) were analyzed and compared using appropriate bivariate tests. Genetic testing was performed among 45% (855/1899) of patients with mPCa (castration-sensitive [mCSPC]: 36%; castration-resistant [mCRPC]: 49%; HRR genes: 43% [34%; 47%]; <i>BRCA</i>: 42% [34%; 46%]). Testing increased from 2020: HRR genes by 17% (p &lt; 0.01); <i>BRCA</i> by 18% (p &lt; 0.01). HRR gene and <i>BRCA</i> mutations were reported in 16% (mCSPC: 13%; mCRPC: 18%) and 15% (13%; 16%) of patients, respectively. In the 2022–2023 DSP, 56% of physicians indicated they were more likely to conduct HRR gene testing following PARPi availability. Patient refusal, costs, reimbursement issues, low sample availability, and result delays were testing challenges. Among 40% of patients who spoke with physicians about testing, 83% were tested, and 49% reported knowing results helped. Understanding physicians’ and patients’ experiences with, and challenges surrounding, genetic testing for PCa may facilitate better clinical-management interactions. <b>What is this article about?</b> Genetic testing for some genes (e.g., homologous recombination repair [HRR], including BReast CAncer [BRCA]) may help guide treatment of patients with metastatic prostate cancer (mPCa). Testing rates and results, and physicians’ and patients’ views of testing, were studied using data from real-world surveys conducted in 2020 and 11/2022–7/2023. <b>What were the results?</b> Almost half of patients with mPCa had genetic testing, about four in 10 had HRR gene or <i>BRCA</i> testing, and testing increased between surveys. Patients seeing medical oncologists were tested more often than patients seeing urologists. As per guideline recommendations, tested patients were younger, had worse disease, and were more likely to have a family history of cancer than non-tested patients. About four in 10 patients had HRR gene mutations, and almost all had <i>BRCA</i> mutations, indicating HRR gene testing beyond <i>BRCA</i> was not yet well-established and/or captured in patients’ records. Many physicians reported that <i>BRCA</i> test results were essential before starting treatment. Patient refusal was an increasing challenge to testing; other challenges were testing costs, testing reimbursement issues, low sample access, and test result delays. Notably, six in 10 patients did not or could not remember talking to their physicians about testing; among patients who did, most were tested and half said knowing results helped. <b>What do the results of the study mean?</b> Increased understanding of physicians’ and patients’ experiences with genetic testing may help physician-patient discussions about testing and PCa management, which likely would benefit from educational materials and tools.