Background: Treatment in advanced prostate cancer (PC) is evolving with the approval of poly-adenosine diphosphate-ribose polymerase inhibitors (PARPi) in patients with homologous recombination repair mutations (HRRm) in metastatic castration-resistant PC (mCRPC). There is little information on the use of biomarker testing for treatment selection. This study describes healthcare providers (HCPs) assessments of their use of biomarker testing, treatment patterns, and factors that drive treatment decisions. Methods: An online cross-sectional survey of HCPs treating advanced PC patients in the US was administered. HCPs were recruited (Aug–Sept 2022) via clinical panels and provided informed consent. Survey questions covered factors influencing HRRm testing and treatment decision-making. Results: Of 100 HCPs, 45% were urologists, 45% oncologists, and 10% pathologists. About 64% HCPs were in community practices and 30% in academic centers. HCPs in academic centers reported a median of 70% (IQR=50–100) of patients are recommended HRRm testing and of those recommended, 90% (IQR=50–99) receive testing whereas HCPs in community centers reported a median of 50% (IQR=25–100) of patients are recommended HRRm testing and of those recommended, 80% (IQR=50–90) receive testing. Prior to and post FDA approval of PARPi, HCPs (urologists, oncologists, pathologists) reported a median of 20% (10%, 25%, 15%) and 64.5% (50%, 80%, 35%) of patients were recommended HRRm testing, respectively. The median testing rate and increase in testing post PARPi approval was lower in community centers vs. academic centers (50% vs. 80% and 35% vs. 55%, respectively). Timing of testing and factors affecting testing are described in Table 1. Most HCPs (59%) recommend testing at diagnosis of or after first-line mCRPC. Limited insurance coverage and patient refusal were common reasons for patients who are recommended HRRm testing to not receive it. Top two factors influencing decision to treat with PARPi were HRRm status (50%) and treatment efficacy (42%). Conclusions: There was an increase in HRRm testing post PARPi approval as reported by HCPs. Surveyed HCPs reported a wide variation in the percentage of mCRPC patients recommended for HRRm testing and stages in the disease course when they recommend testing. Lower percentage of patients are being prescribed testing in community practices compared to academic centers.
Timing of recommending HRRm testing and factors affecting the recommendation and receipt of HRRm testing according to US HCPs.
*Responses not mutually exclusive. Key: ctDNA – circulating tumour deoxyribonucleic acid, HCPs – healthcare providers, HRRm – homologous recombination repair genes, mCRPC – metastatic castration-resistant prostate cancer, mHSPC – metastatic hormone-sensitive prostate cancer, nmCRPC – non-metastatic castration-resistant prostate cancer, PC – prostate cancer.