Prostate Specific Antigen (PSA)

This test is often included in routine physical exams for men older than age 50. Because African American men have higher rates of getting, and dying from, prostate cancer than men of other racial or ethnic groups in the United States, medical organizations recommend a PSA blood test be given starting at age 40 for African American men.

Medical organizations also recommend a PSA blood test be given starting at age 40 for men with a family history of prostate cancer. Some medical organizations even recommend a PSA blood test be given to all men starting at age 40.

If urination problems are present or if a PSA blood test indicates a problem, additional tests may be ordered. These tests may require a patient to change his diet or fluid intake or to stop taking medications. If the tests involve inserting instruments into the urethra or rectum, antibiotics may be given before and after the test to prevent infection.

Why is a prostate-specific antigen (PSA) blood test performed?

A PSA blood test is performed to detect or rule out prostate cancer. The amount of PSA in the blood is often higher in men who have prostate cancer. However, an elevated PSA level does not necessarily indicate prostate cancer. The U.S. Food and Drug Administration has approved the PSA blood test for use in conjunction with a DRE to help detect prostate cancer in men age 50 or older and for monitoring men with prostate cancer after treatment. However, much remains unknown about how to interpret a PSA blood test, its ability to discriminate between cancer and problems such as BPH and prostatitis, and the best course of action if the PSA level is high.

When done in addition to a DRE, a PSA blood test enhances detection of prostate cancer. However, the test is known to have relatively high false-positive rates. A PSA blood test also may identify a greater number of medically insignificant lumps or growths, called tumors, in the prostate. Health care providers and patients should weigh the benefits of PSA blood testing against the risks of follow-up diagnostic tests. The procedures used to diagnose prostate cancer may cause significant side effects, including bleeding and infection.