There are two prostate cancer screening tools in widespread use in the United States today: PSA testing and DRE. Despite the fact that both tests have been used for nearly twenty-five years, there remains some controversy on their utility.
PSA is a protein secreted by the prostate gland that is detected in the serum. It is produced in low levels by the normal prostate, and at increased levels in both prostate cancer and in benign prostatic hypertrophy (BPH), a benign condition of diffuse prostate enlargement. The normal range for PSA is 0-4 ng/dL, and the risk of prostate cancer is 25-fold in men with a PSA greater than 10 ng/dL (51). PSA is falsely elevated in patients with BPH and inflammation of the prostate gland. The false positive rate has been estimated to be between 30-50% in men with BPH, and the false negative rate (occurrence of prostate cancer in men with a normal PSA) is approximately 15% (52).
The DRE is a physical exam technique in which a healthcare provider manually palpates the prostate gland for tumors. This method may allow for the detection of lesions that are in the posterior peripheral areas of the prostate gland, and is not considered to be a highly sensitive diagnostic test. However, it is fairly specific, as 25-50% of men with an abnormal DRE will have prostate cancer.
Although both DRE and PSA testing have shortcomings, they are currently the only screening methods available to detect prostate cancer, and the incidence and mortality from this disease have declined since the mid-1990s when these screening tests came into widespread use (50). There is controversy among the national guidelines on when and how often to screen men for prostate cancer, but the most rigorous approach adapted by both the American Cancer Society and the American Urological Society recommend annual DRE and PSA testing beginning at age 50, and to continue until the patient’s life expectancy is less than ten years (50). Men with a first-degree relative with prostate cancer or African American ethnicity should be screened beginning at age 45 (50).