Use of PSA threshold to identify an increased 4-year risk of a prostate cancer diagnosis in U.S. men

Abstract

5051 Background: Recent studies have shown that prostate specific antigen (PSA) values can be used to predict risk of developing prostate cancer (PCa) in the future. In the European Randomized Study of Screening for PCa (ERSPC) subjects with PSA of ≥1.5 ng/mL had a significantly greater risk of developing PCa after 4 years than subjects with PSA of <1.5 ng/mL (9.2% vs 1.5%, respectively; OR = 7.466; p < 0.001). This current analysis aimed to validate the ability of PSA of ≥1.5 ng/mL to predict the future risk of PCa in a US population of men within the Henry Ford Healthcare System (HFHS). Methods: This is a retrospective analysis of men enrolled in the Health Alliance Plan of the HFHS between 1997–2004 with at least 4 years of follow-up data. Men ≥40 years of age, with a baseline PSA value between 0–4.0 ng/mL, not receiving 5-alpha reductase inhibitors were included. Men were followed for 4 years after their first PSA value. The risk of 4-year PCa diagnosis was evaluated based on a 1.5 ng/mL PSA threshold, and was assessed by logistic regression, controlling for age and race. Results: A total of 21,502 patients were included in the analysis. At baseline, patients had a mean age of 55 years and a mean PSA of 1.0 ng/mL. Overall, 7.9% of patients with baseline PSA of 1.5–4 ng/mL were diagnosed with PCa after 4 years, compared to 0.5% of patients with a baseline PSA of <1.5 ng/mL. In a multivariate analysis (controlling for race and age), patients with a baseline PSA of 1.5–4 ng/mL were 12 times more likely to be diagnosed with PCa over 4 years than patients with baseline PSA of <1.5 ng/mL (OR = 12.4; 95% CI: 9.7–15.9; p < 0.0001). African Americans (n = 6,367) with baseline PSA 1.5–4 ng/mL vs baseline PSA<1.5 ng/mL had an even higher risk of being diagnosed with PCa over 4 years (OR = 17.0; 95% CI: 11.0–26.1; p < 0.0001). Conclusions: This analysis validates that men with PSA values 1.5 to 4 ng/mL are at a significantly increased risk for developing future prostate cancer compared to those with a PSA value below the 1.5 threshold. This threshold also confers increased 4-year risk in African American men. [Table: see text]