Prostate-specific antigen 1.5-4.0 ng/mL: a diagnostic challenge and danger zone

OBJECTIVES To assess the value of a PSA threshold of 1.5 ng/mL as a predictor of increased prostate cancer risk over a four-year period based on a man's first PSA test, including racial differences. To review the risk of progression of benign prostatic hyperplasia (BPH) based on a similar PSA threshold. PATIENTS AND METHODS A retrospective review involving 21 502 men from a large Midwestern health system was performed. Men at least 40 years old with baseline PSA values between 0 and 4.0 ng/mL and at least four years of follow-up after initial PSA test were included. Optimal PSA threshold and predictive value of PSA for development of prostate cancer were calculated. RESULTS Prostate cancer rates were 15-fold higher in patients with PSA >= 1.5 ng/mL vs patients with PSA <1.5 ng/mL (7.85% vs 0.51%). African American patients with baseline PSA <1.5 ng/mL faced prostate cancer rates similar to the whole study population (0.54% vs 0.51%, respectively), while African American patients with PSA 1.5-4.0 ng/mL faced a 19-fold increase in prostate cancer. CONCLUSION Both Caucasian and African American men with baseline PSA values between 1.5 and 4.0 ng/mL are at increased risk for future prostate cancer compared with those who have an initial PSA value below the 1.5 ng/mL threshold. Based on a growing body of literature and this analysis, it is recommended that a first PSA test threshold of 1.5 ng/mL and above, or somewhere between 1.5 and 4.0 ng/mL, represent the Early-Warning PSA Zone (EWP Zone). This should serve to inform patients and clinicians alike to future clinical activities with respect to prostate cancer and BPH.