Okay, I had a consultation with the surgeon yesterday and discussed with him the advice of the onco.
He said that he he didn't agree with the onco and that his advice is out of date. There is a 1/3 chance that my disease is already metastatic and, if it is, blasting away at the prostate bed and administering hormone treatment will achieve nothing outside of making me miserable.
Evidently what happens is that men follow that course of action and see their PSA drop to undetectable, only to see it rise again after the cessation of HT, because the PSA wasn't ever coming from the prostate bed.
He is still saying that I should have a PSMA PET scan at 0.2 and hope that it shows something. If it does, target the area. If mets later present elsewhere, have a go at those. I won't have had a lifetime's dose of radiation to the pelvis. If it shows nothing we need to talk again.
He is discussing my case with a MDT this week and will report back.
I also asked him what the natural history of my disease would be without treatment. He said that if I would otherwise have lived my normal lifespan, that the cancer would at some point overtake me an kill me. But it would probably be many years before that happened.
Since the meeting I have pondered what would have happened if I had never had an RP. How long would I have lasted? How long might I last if I take no further action?
I am not yet persuaded that "survival at any price" is the correct course of action.