Diagnostic triad for early detection of prostate cancer. Digital rectal examination (DRE), measurement of the protein prostate-specific antigen (PSA) in sera, and transrectal ultrasound (TRUS)–directed prostatic biopsy comprise a diagnostic triad for early detection of prostate cancer. A, DRE usually is performed with the patient bent at the waist 90° over the examining table, feet spread about 2 feet apart, and knees slightly bent. The normal prostate should have the consistency of the thenar eminence of the thumb when the thumb is apposed to the little finger. Prostate cancer should be suspected when the consistency is firmer than normal, or distinct nodules are present. B, PSA can be detected in sera by immunoassay and most commonly is elevated in the presence of prostate disease that occurs with age. C, TRUS is performed, with the patient on his side, by gently inserting an ultrasound probe into the rectum. Prostate biopsies can be visually directed using a biopsy gun loaded onto the TRUS probe.

Although controversy exists regarding the benefits of early diagnosis, it has been demonstrated that an early diagnosis of prostate cancer is best achieved using a combination of DRE and PSA as first-line tests to assess the risk of prostate cancer being present. When DRE and PSA are used to detect prostate cancer, detection rates are higher with PSA alone than with DRE alone, and highest with a combination of the two tests. Because DRE and PSA do not always detect the same cancers, the tests are complementary. TRUS is not recommended as a first‐line screening test because of its low predictive value for early prostate cancer and the high cost of the examination. TRUS-guided, systematic needle biopsy currently is the most reliable method to ensure accurate sampling of prostatic tissue in those men at high risk for harboring prostatic cancer based on DRE abnormalities or PSA elevations. (Adapted from Resnick and Older [4] and Tanagho [5]; with permission.