Your understanding of free PSA in your 2nd post is roughly correct, except for the word "quite" in your phrase "quite low."
It's important to put all that data into context of the big picture. Autopsy studies of men (of all ages) who died of accidental causes revealed that the probability of someone have at least a detectable amount of prostate cancer is roughly equal to his age.
So roughly 59% of your fellow 59-year olds have some prostate cancer.
Given the ubiquity of prostate cancer, it's not so important whether you have PC or not, it is whether you have an advanced form of PC that needs treatment or not. This is why Advance Surveillance is the best choice for favorable-risk cases.
The purpose of performing a biopsy on a 59-year old is NOT to look for prostate cancer--we already know that in all likelihood he does. Rather, the purpose is to see if the biopsy samples indicate the case is favorable or unfavorable category.
Keep the big picture in mind...
Post Edited (JackH) : 3/31/2016 1:49:00 PM (GMT-6)