I'll let someone else take the RT/prostate size question. Yes, G6 (3+3) is cancer, and, although it can't metastasize, it can grow out from the prostate. Here is what J. Epstein wrote on this topic: Should Gleason 6 be labeled as cancer?
[2015, Full Text]
Even if all your cores were G6, there are too many for you to be a good active surveillance candidate. The overall Gleason score of a biopsy is that of the highest G found, so even if JH comes back with a single G4 (3+4) core, you would still be in the Intermediate Favorable Gleason Grade Group.
Post Edited (DjinTonic) : 1/18/2020 4:41:42 PM (GMT-7)