StevenJS said...
My doc is giving me ambiguous information on my PSA numbers, so I am trying to figure out if I need to go to another. What does a "PSA, Free" value of .65; "% Free PSA" of 15.5; and a ""PSA Value" of 4.2 imply? THANKS!
That's great that you received the full PSA report; this is meaningful information. It's not "ambiguous;" you just need an explanation of what it means. Here's what you need to know:
Your blood's "PSA Value" (which was 4.2 ng/mL, or nanograms per milli-Liter) is comprised of two forms of PSA. The "PSA Value," or total PSA, is the sum of both forms. Total PSA is the information typically reported on a standard PSA test, and is most commonly discussed. In the absence of specifying "total PSA" when one is talking about
a PSA test, one is talking about
the total sum of the two constituents and referring to it simply as "PSA;" so when someone says "My PSA was 6," they are talking about
their total PSA.
The two forms are i) "bound PSA" and ii) "unbound PSA," or "free PSA." You don't need to know too much about
these, but basically the "bound" means it is attached to a protein in the blood, while the "unbound, or free" is not. Suffice it to say that research shows that a higher amount of free PSA in a test means a lower chance of prostate cancer. (see the table in John_TX's link...but know that this table is just a rough indicator) Please note, too, that this has absolutely nothing to to with whether the cancer may be aggressive (rare) or the much more common benign forms of prostate cancer...that info is evaluated elsewhere, later.
So, your Total PSA was 4.2 ng/mL. (There is an age-specific range for PSA thresholds, but 4-10 ng/mL is generally considered "the grey zone" where it's probably appropriate to start looking into why it is slightly elevated...knowing that there may be several causes, either cancerous or benign.)
One of the two constituents of your Total PSA is the Free PSA, which was 0.65 ng/mL.
The percent of Free/Total PSA is equal to 0.65 / 4.2 = 0.155, or 15.5%.
clear? helpful?
-Norm
Post Edited (NKinney) : 12/22/2017 9:47:57 AM (GMT-7)