The purpose of screening is early diagnosis and treatment. Screening tests are administered to people who may be at high risk for certain diseases or conditions, but do not have any symptoms.

Screening guidelines and tests

A blood test called PSA may be used to screen for prostate cancer. There are some important factors when considering using a PSA test. First, there is not a clear normal level of PSA. This can lead to:

  • False positive—Some men may have elevated levels but be perfectly healthy. This could lead to additional tests and anxiety before it is confirmed that cancer is not present.
  • False negative—PSA is normal but cancer is present. This may give a false sense of security and delay treatment.

Second, many types of prostate cancer grow very slowly. A PSA test may reveal a small tumor that is not causing symptoms and would not impact health before natural end of life. A positive PSA test, even if cancer is present, may lead to unnecessary tests and procedures for a cancer that would have never needed treatment. Because of this, most organizations advise that men talk to the doctors about the risks and benefits of PSA screening. It is important to talk to your doctor about harms and benefits of using PSA for screening tests.

The PSA test measures the levels of PSA in your blood. PSA is a chemical produced in the prostate gland and released into the bloodstream. Since prostate cancer is an overgrowth of abnormal prostate cells it can increase the amount of PSA in the blood. However, an elevation in PSA levels may also happen because of:

If your PSA is elevated, it does not necessarily mean cancer is present. Other tests will be done to find the reason for increased PSA levels. Next steps may include:

  • Physical exam (which includes a digital rectal exam) to test for enlargement of prostate
  • Repeating the test at a later date
  • Ultrasound or urine tests
  • A prostate biopsy to look for the presence of cancer