I have been on zytiga for well over a year. My PSA went from a 3 and the highest it's been since I've been on zytiga was a .57 and at this time is now down to a .27 . When I was diagnosed my PSA was at an eight and they decide to do a biopsy and they said my my biopsy was a 7. I was treated with couple different drugs before they decided to follow up with chemotherapiy for 21 weeks and after the chemo they put me on zytiga I am trying to get my insurance to allow me to go to the Mayo Clinic to get a second opinion to see if I've got stage 4 prostate cancer. I have never experienced any pain with this stage 4 and they said there was a couple small areas in the pelvic girdle that look like it might be cancer but now with ones bone scans I can't find that. That is why I'm trying to get my insurance company to allow me to go to get a second opinion. I am tired of taking drugs. Good luck to you and don't worry cuz it is what it is.