In asymptomatic patients, positive predictive value for cancer is 67% for PSA > 10 ng / mL (10 mcg / L) and 25% for PSA 4 to 10 ng / mL (4 to 10 mcg / L); recent evidence indicates a 15% prevalence of cancer in men ≥ 55 years old with PSA < 4 ng / mL (4 mcg / L) and a 10% incidence with PSA between 0.6 and 1.0 ng / mL (0.6 and 1.0 mcg/L).