My doc says my cut-off is at PSA = 2.0, then it is on to intermittent luprolide + a round 2 chem. PSA hit 1.58 Nov, doubling time has been all over the place with a 3 month freeze this past summer. It doesn't take a crystal ball to see my path, however.
I try to make sure that I hurt pretty much all over all of the time any more. That way, there is no single pain item that precludes my normal life activities.