SEPTA Trial: Stockholm3 Validation Study in a Multi-Ethnic Cohort for ProsTAte Cancer

Introduction: Prostate cancer (PCa) is the most commonly detected cancer in men and is the second leading cause of cancer death. Differences in race and ethnicity have been shown to have differences in PCa incidence, detection, and outcomes. Current prostate cancer screening involves prostatic specific antigen (PSA) which is a nonspecific protein marker (aka kallikrein) that can often leads to unnecessary biopsies (up to 74% benign biopsies) and clinical overdiagnosis (with up to 22% clinically insignificant cancer). Recently more sophisticated tests have been developed for PCa screening in the United States such as the Prostate Health Index (PHI) and the 4k (kallikrein) score, as well as clinical models that use information from the patient clinical history. However, these tests utilize limited serum protein assays and none of the established screening protocols utilize genetic variables to help account for the likely inherited risks as seen in different ethnicities.

A recent Swedish, prospective, population-based study, published in the Lancet Oncology, developed a unique multivariable biopsy outcome prediction model within a Nordic population of nearly 60,000 men. This model, the Stockholm3, which incorporated plasma protein markers, germline DNA SNPs as well as clinical variables, was shown to be capable of reducing the number of biopsies by 44% compared to PSA while maintaining adequate sensitivity for detection of PCa.

It is unknown whether an approach developed in Sweden that incorporates protein markers, genetics, clinical variables, and genetic ancestry would be beneficial in a racially diverse cohort.

Hypothesis: The investigators hypothesize that, a prospectively studied multiethnic cohort of men with the Stockholm3 test will identify unique and common risk factors that improve prostate cancer detection.

Aim: To assess the performance of the Stockholm3 test as compared to PSA and to identify unique features associated with PCa in Black/African American (n=500), Asian (n=500), White/Caucasian Hispanic (n=500), and White/Caucasian Non-Hispanic (n=500) men.

Methods: The investigators propose a prospectively identified cohort with participating institutions which have screened positive to undergo a prostate biopsy to have a retrospective analysis the Stockholm3 test and ancestry markers. Within this cohort the investigators will examine several predetermined risk factors to investigate their relationship to prostate cancer.

This blood sample will be tested for quantitative levels of serum protein markers and DNA will be extracted and will be tested for germline mutations as defined by the Stockholm3 test and other ancestry informative markers. Results from the study will be presented in such a way that no individual information will be disclosed.