Good source info Peter- fPsa is about
the unbound antigens- here is some statistical stuff to ponder upon:
The higher the percentage of fPsa number you have the better, lower like 0-10% fPsa is the bad news of over 50% chance of PCa being found. Oh.....normal psa testings of over 10.0 ng/ml are considered inaccurate or much less reliable for fPsa tests and they also mention 4.0 as the lower end of accuracy, it must be technical on why this is the range of decent reliability.
Probability of finding prostate cancer based on % free PSA in men with a total PSA between 4 ng/ml and 10 ng/ml
% free PSA (below see percentage range, then below see percentage odds of having PCa found):
Probability of prostate cancer
0%–10% (fPsa)
56%
10%–15% (fPsa)
28%
15%–20%(fPsa)
20%
20%–25% (fPsa)
16%
Greater than 25% (fPsa)
8%
SOURCE: Journal of the American Medical Association, May 20, 1998.
Post Edited (zufus) : 12/6/2012 2:56:51 PM (GMT-7)