Bottom line: No cut-offs have both high sensitivity and high specificity; there is evidence that cut-offs for PSA vary by age and race.
Summary: Morgan TO, et al. Age-specific reference ranges for prostate-specific antigen in black men. N Engl J Med 1996 Aug 1;335(5):304
Case-control study measured serum PSA in 3475 men with no clinical evidence of prostate cancer (1802 white and 1673 black) and 1783 men with prostate cancer (1372 white and 411 black). RESULTS: Cut-offs that had 95% sensivity for black men by age: 40-49 PSA > 2 ng/mL; 50-59 years PSA > 4 ng/mL; 60-69 PSA > 4.5 ng/mL; 70-79 PSA > 5.5 ng/mL. For white men by age: 40-49 PSA > 2.5 ng/mL; 50-79 PSA > 3.5 ng/mL.
Also, see PSA Screening in DynaMed.