What is a prostate-specific antigen test?
Definition Prostate-specific antigen, or PSA, is a protein produced by the prostate gland that may be found in elevated levels in the blood when a person develops certain diseases of the prostate, notably prostate cancer. PSA is specific, because it is present only in prostate tissue. It is not specific for prostate cancer, however, as it may also be elevated in men with benign enlargement of this organ. The PSA test has been called the “male PAP test.” Purpose The blood test for PSA is used to screen older men to detect prostate cancer at an early stage, and also to monitor its response to treatment. After lung cancer, prostate cancer is the most common form of cancer in men in the United States. Any routine physical exam of a man aged 50 and older should include a digital rectal examination (DRE), in which the doctor’s finger probes the surface of the prostate gland to detect any suspicious area of hardness or a tumor mass. If the examination suggests that a tumor may in fact be pres
