I am nearly 15 years post prostatectomy for Gleason 9 (4+5) with technically clear margins (pathologist saw tumor within 0.1 mm of capsule-bet he wouldn't call that "clear" if it were his prostate). My PSA was 0.4 at 4 months and nearly 0.8 at 8 months so a doubling time of 4 months (don't buy green bananas). I had radiation and ADT for 18 months and PSA went to .001 (really! I was in Honduras and they had an excellent lab if you believe those numbers). Gradually my PSA rose to ~3.0; I saw an oncologist in Charleston, SC who got me on a close to vegan diet, pomegranate supplement, Vit D (mine was borderline low) and my PSA stayed stable for a year or so and then started rising again. That oncologist got me into a study at NIH consisting of Smallpox vaccine combined with PSA (only good for those of us old enough to have gotten smallpox vaccine as a child) and then 6 or so booster shots with some "bird pox" vaccine plus immune boosters. Those had almost no side effects (sometimes I felt achy and tired for 24 hours after the shots) and controlled my cancer for 5 years without other treatment during which time my doubling time went as high as 30 months. That lost its effect after 5 years and I repeated the treatment in a follow up study and got little to no effect and developed multiple mets. I did taxotere chemo, and started on and have continued on Lupron and Nubeqa (daralutamide) and my PSA has been undetectable now for 2 years.
That is just my course with the oncologist at MUSC (Charleston, SC) and now at UC Health (Denver, CO). The only thing I would suggest would be close follow up with an oncologist and consider the study at NIH with Dr. Ravi Madan if the idiots in Washington have not quashed its funding.