Free PSA
PSA circulates in the blood in two forms — either attached to certain blood proteins, or unattached, which is called free. The percentage of free PSA is one of the variations of the PSA test.
Why it matters: A provider might use other ways of interpreting PSA results, intended to improve the accuracy of the PSA test as a screening tool. Where there is a high PSA level but a low percentage of free PSA, it may be more likely that prostate cancer is present. Researchers continue to investigate variations of the PSA test to determine whether they provide a measurable benefit.
Source · Mayo Clinic — what it is, why it matters
What is Free PSA?
PSA circulates in the blood in two forms — either attached to certain blood proteins, or unattached, which is called free. The percentage of free PSA is one of the variations of the PSA test.
What might a high or low Free PSA mean?
A provider might use other ways of interpreting PSA results, intended to improve the accuracy of the PSA test as a screening tool. Where there is a high PSA level but a low percentage of free PSA, it may be more likely that prostate cancer is present. Researchers continue to investigate variations of the PSA test to determine whether they provide a measurable benefit.