That was a great response to chemo; that and the Zytiga have shrunk the cancer to the point where the scan won't pick it up (but unfortunately, it's still there). They generally want to see some radiographic evidence of progression before they give up on Zytiga entirely. Sometimes he can get a little extra mileage by switching to Xtandi. Did his original bone scan show bone involvement? If so, Xofigo may be a good next step, perhaps combined with Provenge (they play together well). He can also re-do the docetaxel or upgrade to cabazitaxel. Sometimes re-challenging with Zytiga or Xtandi afterwards can be beneficial.
As for treating the prostate ("debulking"), that is experimental at this point. There are some good clues that it may still have some benefit:
There are also several clinical trials that he may be eligible for.
Allen - not an MD
•PSA=7.3, prostate volume=55cc, 8/17 cores G6 5-35% involvement
•SBRT 9 yr onc. results
•SBRT 7 yr QOL results
•treated 10/2010 at age 57 at UCLA,PSA now: 0.1,no lasting urinary, rectal or sexual SEsmy PC blog