Prostate (Free PSA) in the event of a PSA result

PSAF (S) can be ordered only as a post-test or in combination with PSA.

This test can only take place if PSA total has been tested in our laboratory. You will be called to ask if you would like to perform this re-test on blood already in our possession.
If the PSA total is greater than 4.0 then free PSA can be added.


Recent research has shown that most life-threatening prostate tumors grow very slowly. As a result, the PSA rises only slowly. The influence of prostate enlargement and inflammation is then so great that the ability to predict aggressive tumors from an elevated PSA level is completely gone.

The interpretation of the PSA results is not easy because the PSA level in the blood increases with age, without any abnormality of the prostate.
Over 50 years of age, 2 out of every 10 men (20%) have an elevated PSA value. This increased value can indicate prostate cancer, but also occurs with benign prostate enlargement, a urinary tract infection or a prostate infection. Therefore, an elevated PSA value always requires additional tests. However, the higher the PSA value is, the more likely it is that prostate cancer is present.

As the prostate ages and grows, the PSA will also increase.
When the PSA total > 4.0 then free PSA can be added.
From a PSA above 10, the calculation of free PSA is no longer reliable, as a follow-up to the result of PSA total.

If you report this directly, there is no need for a new blood test and you can have this test done in the existing blood.

In case of elevated PSA total, we recommend testing the free PSA.
In a recent USA study, the following limits for total
PSA were given for different age groups: Average normal values by age group.

Age: Normal value is smaller than

• 40 - 49 years : 2.50 μg/l
• 50 - 59 years : 3.50 μg/l
• 60 - 69 years : 4.50 μg/l
• 70 - 79 years : 6.50 μg/l

Incidentally, other factors such as frequent cycling, horseback riding, prostatitis or benign prostate enlargement can also result in an increased PSA total.

The ratio of free PSA to Total PSA only provides information if the total PSA is significally elevated. In benign prostate disease, the ratio of free PSA to total PSA is usually
greater than 0.2. But this result gives no information if the total PSA is
non-significantly elevated.