Measurement of prostate-specific antigen in serum as a screening test for prostate cancer

Abstract Background. Prostate-specific antigen (PSA) is secreted exclusively by prostatic epithelial cells, and its serum concentration is increased in men with prostatic disease, including cancer. We evaluated its usefulness in the detection and staging of prostate cancer. Methods. We measured serum PSA concentrations in 1653 healthy men 50 or more years old. Those with PSA values ≥4.0 μg per liter then underwent rectal examination and prostatic ultrasonography. Ultrasound-directed prostatic needle biopsies were performed in the men with abnormal findings on rectal examination, ultrasonography, or both. The results were compared with those in 300 consecutively studied men 50 or more years old who underwent ultrasound-directed biopsy because of symptoms or abnormal findings on rectal examination. Results. Serum PSA levels ranged from 4.0 to 9.9 μ9 per liter in 6.5 percent of the 1653 men (107). Nineteen of the 85 men in this group (22 percent) who had prostatic biopsies had prostate cancer. Serum PSA leve...