Perhaps I am thick, but one thing I have never properly understood is how much PSA a healthy man should have?
As I understood it PSA should be contained within the prostate, but as we get older and the prostate expands either through cancer or benign expansion the structure of the prostate gets a little distorted and PSA leaks out. I have thought of it like a car engine, when it is new all the oil stays inside, as it gets older, with worn bearings and gaskets some oil starts to leak?
So a man in his sixties, with no symptoms of PCa and a PSA level of 3 or even 4 is considered healthy? I wonder what PSA level is found in a healthy man in his 20's or 30's?
A decent size tumour will give quite a high PSA level, mine was 30 at diagnosis and the PCa was still contained within the gland, guys whose PCa has metastasised often have a PSA level in the hundreds.
So for men who have had RP, which has left some healthy prostate tissue at the margins are likely to have some PSA produced by those healthy cells. In the same way they go to a lot of trouble with EBRT to focus the beams on the cancer, and ditto with Brachytherapy they use the template biopsy to determine where to place the rods, they don't simply irradiate the entire prostate gland.
So whatever treatment we have had we should all be left with a few healthy bits and pieces of prostate that might be expected to produce some PSA.
So why do the doctors get concerned about such low levels of PSA?