Serum prostate-specific antigen (PSA) concerns are correlated directly with age, and the recommended upper limit of normal serum PSA values for men is: 2.5 ng/ml for 40 to 49 years, 3.5 ng/ml for 50 to 59 years, 4.5 ng/ml for 60 to 69 years, and 6.5 ng/ml for 70 to 79 years.