Surgery is very uncommon after metastasis just because the cancer has already left the prostate, so there's little justification for putting the patient through the extra trauma of surgery.

There's still the option of radiating the prostate, though, and it's just as effective — that's something to discuss with his care team.

Some oncologists believe that neutralising the "mothership" (the primary cancer) reduces support for the metastases and slows progression — it's a relatively new concept, which Dr Walsh discusses in the book linked earlier in this thread.

A "triplet therapy" approach for your husband might involve chemo, radiation, and ADT close together to try to give the cancer a 1-2-3 knockout punch (vs the old-school approach of one thing until it stops working, then the next, etc, until they tell you you're out of options😢), but it's a tough decision. I'm glad I went with a big, multi-pronged, up front attack on my metastatic cancer (my oncologist called it "throwing the kitchen sink" at it), but everyone's situation is different.

I wish all the best to both of you.