Artist Mark - amen, brother. I have the same thoughts. I've searched Dr. Google so much all the links come back purple, that I've looked at them already. I've searched BCR vs Gleason score endlessly, with no success. As far as I can see, there just aren't studies to show the BCR PSA levels vs Gleason score. It's been a long time, but there was a study showing PSA production for various Gleason cell types. I gotta dig for that one...
So cases like mine, that's all G9, show a relatively low PSA (say 5.2), but in reality with a lower G score that would be more like 15 or more.
Man, it took me a while to find this thread! I remembered JNF and I talking about
this a long time ago.Do Gleason 9s not make much PSA?
from JNF's June 17, 2013 entry:Benign prostate cells give off about .066 PSA per cubic centimeter of mass. Cancer gives off much more PSA per cc of mass and in declining order. Gleason 6 gives about 4 PSA per cc, G7 is about 3 PSA per cc, G8 about 2 PSA per cc, G9 about 1 PSA per cc and G10 less than 1 PSA per cc. These are my roundings of the averages from Strum's work in his book.
So, if the Phoenix definition of recurrence is 2 ng/dl above the nadir level after RT, is that true for ALL types of PCa? Or, would G9 cases be "recurring" at 1/3 to 1/4 of that? It's not clear that this was even a factor in the establishment of the Phoenix criterion.
The pattern is probably more important. In other words, if you have a low PSA but with a steady increase, with a reasonably short doubling time, it would be worth more investigation. Cancer cell growth is based on cells dividing, hence the doubling time. If the pattern looks like that, then that may be important (the log of that trend would be linear, with a doubling time of less than a year or so).
If the PSA quantity is low but wandering around, then don't be so concerned. My MO said he's treating a patient, not a number!