Total & Free PSA
(Prostate Specific Antigen)

 

PSA is produced normally by the prostate gland and most of it is released into the semen. A small amount will enter the blood stream and can be measured by taking a blood test. In conditions which affect the prostate (not just cancer) where the architecture of the prostate is altered, more PSA is released into the blood stream leading to a raised PSA in a blood sample.

The PSA indicates your risk of having prostate cancer. It does not diagnose the disease itself. Therefore if you have a PSA greater than 10ng/ml, you will have a 50% chance of having prostate cancer. If your PSA is between 4-10 ng/ml, you will have a 25% chance of having prostate cancer. However even if your PSA is below 4ng/ml, it does not mean you do not have cancer but you would be at very low risk of having cancer. Oesterling JE. Prostate specific Antigen: a critical assessment of the most useful tumour marker for adenocarcinoma of the prostate. J Urol. 1991. 145, 907-923.

PSA can also be elevated due to:

• An enlarged prostate
• Prostatitis
• Catheterisation
• Prostate Surgery
• Urinary Tract Infection

A normal result may provide reassurance but does not absolutely rule out prostate cancer.

An elevated result may cause anxiety and may not lead to a diagnosis of prostate cancer.

PSA remains the best tumour marker for prostate cancer. It will lead to the diagnosis of men with prostate cancer, allow early treatment and then is used as a marker for monitoring treatment success.

PSA testing may be performed when a man has symptoms suggestive of prostate cancer such as difficult, painful, and/or frequent urination. It may also be ordered during and at regular intervals after prostate cancer treatment. Or to help determine the necessity for a biopsy of the prostate, to monitor the effectiveness of treatment for prostate cancer, and to detect recurrence of prostate cancer.