Prostate Cancer Risk Identification in a Multi-Ethnic Cohort: a Prospective US-based Multi-center Validation Study of Proclarix

Prostate cancer remains a leading cause of cancer-related morbidity and mortality in men worldwide, with significant disparities in incidence and outcomes across different ethnic groups with black men being affected by prostate cancer earlier, more frequently and with more aggressive disease. Current risk stratification tools often lack the precision needed to effectively assess and predict prostate cancer risk in diverse populations. Proclarix® is a blood-based test that addresses the problem of prostate cancer (PCa) overdiagnosis by indicating the risk of clinically significant disease. It is comprised of two novel biomarkers, thrombospondin 1 (THBS1) and cathepsin D (CTSD), and is combined with total prostate-specific antigen (tPSA), free PSA (fPSA) and age. A software algorithm returns a risk score that can be used as an aid in the identification of clinically significant PCa (csPCa), defined as International Society of Urological Pathology (ISUP) Grade Group ≥ 2. Proclarix® has been developed and validated on 955 men, in majority of Caucasian background with 90% sensitivity, 43% specificity, 95% negative predictive value (NPV) and 25% positive predictive value (PPV). The validation performance established on German and Austrian patients has been fully confirmed in other European populations: the United Kingdom, Spain, Denmark, Italy and Switzerland. To be used broadly, confirmation of Proclarix® performance in patients from diverse ethnic backgrounds requires further investigation.