[Prostate specific antigen: a role of PSA in the diagnosis of prostate cancer]

Early diagnosis of prostate cancer is best achieved using a combination of DRE and PSA as first-line tests to detect signs of prostate cancer. Because DRE and PSA do not always detect the same cancer, the tests are complementary. Among men with elevated PSA who are negative on DRE, the chance of cancer ranges from 12 to 32%. Most men with PSA elevations do not have cancer. This high false-positive rate among men without cancer has led to many approaches to decrease the incidence of false-positive test results, including PSA density, transition zone PSA density, PSA velocity, age-specific PSA reference ranges and percent free PSA.