Biomarker testing patterns among patients newly diagnosed with prostate cancer in a community oncology network.

229 Background: Prostate cancer guidelines recommend that clinicians order biomarker testing for patients with metastatic prostate cancer. In addition, testing is recommended to determine patients’ eligibility for clinical trials and to identify potential actionable mutations that can inform appropriate treatment strategies. The aim of this study was to evaluate biomarker testing patterns among patients newly diagnosed with prostate cancer who received care in a large community oncology provider network. Methods: A retrospective database analysis, using several sources that include iKnowMed (EMR), Ellkay CareEvolve (Genetic HL7 interface), and the Molecular Data Warehouse and covers approximately 1.7 million distinct patients, was conducted on patients newly diagnosed with prostate cancer between Jan 1, 2018, and Jun 30, 2022, and receiving care in a large oncology network in West South-Central United States. Baseline demographics and clinical characteristics were analyzed descriptively and the proportion of patients who received biomarker testing was determined. Results: Data on 18,743 patients with prostate cancer (mean age at diagnosis, 71 years; 46% White, 13% Hispanic, 7% Black, 1% Asian, 33% other/unknown) were abstracted. The proportion of patients who received biomarker testing was 14% overall and 23% among those with Stage IV disease. Of all biomarker tests performed, roughly 6% was single gene testing, 49% was broad panel testing, 25% was both single gene testing with broad panel testing, and approximately 20% of the tests were unknown. The average time from first biomarker testing to disease diagnosis was approximately 5 months. Less than 10% of the patients who tested positive with an actionable mutation received targeted therapy. Hormone therapy (32%) was the most common treatment received, followed by supportive care (7%). Conclusions: These findings provide insights into the frequency of biomarker testing among patients newly diagnosed with prostate cancer who receive care in a large community practice setting. Advancement in targeted therapies is predicated on improved testing rates, and this study suggests opportunities exist for interventions and increased education among healthcare providers based on observed time to testing and the rate of testing. Biomarker testing patterns in patients with prostate cancer. Parameter Patients with prostate cancer(N=18,743) Received biomarker testing All patients, n (%) 2,585 (14) Patients with metastatic Stage IV disease, n/n (%) 941/4,168 (23) Received targeted therapy after positive biomarker testing indicating actionable mutation, n/n (%) 36/450 (8) Mean (standard deviation) days from ordering biomarker test to: Disease diagnosis 156 (545) Receiving results 52 (213) Treatment initiation 113 (525)