Apparently, there is a study conducted by Xtandi. This were randomly selected to include all different levels. Their conclusions is those who were given ADT + Xtandi had a recurrence rate of 10%. That would be somewhat at odds with your figure, which is possibly drawn from an older study. The science has made such progress some times the studies do not catch up. So do give you a warning in the footnote that the study may not be current etc etc.
The presumption here is if you have chemo on top, ie triplet treatment, the outlook would be even better.
At the end of the day, regardless of staging, it depends on your treatment and how well you respond to it. The best case is if the PSA falls by 90% in the first month, and < 0.1 within 4-6 months.
Some may have stage 3 but does not respond well. That may be more serious than stage 4 that responds well.
Also remember that recurrence does not necessarily mean terminal as far as PC is concerned.
Dont mind me. I am just another layman trying to make some sense of the whole thing.

Diagnosed with 4b last October. PIRADS 5, Gleason 6-9's and 3-7's. Age 69. My oncologist said no guarantees or promises, but usually he can get at least 10 years for someone in my situation. Cancer spread to 3 lymph nodes, pelvic bones and femur bones.
Started docataxel chemotherapy right away, along with Nubeqa and Eligard. After 6 chemo treatments PET scan showed two tiny spots of cancer remaining. Still taking Nubeqa and Eligard, probably for one year. PSA has gone from 40 to .06. I have an MRI and PET scan scheduled for June and my oncologist thinks the two remaining cancer spots may be gone. Fingers crossed. So, no surgery or radiation and I'm feeling good. Thanks to everyone in this group. The information is excellent.

Take care,
Steve

The doctors really do not know how long you will live with this disease. I have a friend that coming up to his 9 years anniversary. He started de novo with cancer in his lymph system and a PSA over 1400. Everyone responds to treatment differently. I just had my 2 year appointment with my oncologist and she said some patients get radiation, ADT, an ARSI (darolutamide, apalutamide, xdandi) and 6 chemotherapies (docetaxel). For some men, their PSA continues to rise and they do not respond. Even with a few metastases. On the other, some men with a higher volume of metastases receives the same treatment and their PSA drops < 0.100 and stays there for many many years. If we were all being honest, this disparity is what scares us, because you just do not know how you will respond to treatment. One man's Adenocarcinoma cancer is different that another's. This drives me crazy, because I am software developer. I deal in logic and repeatable facts. This all seems like gambling to me. Regardless, my oncologist said I have beaten all the milestones and odds. I think you know when know when you know. My cancer is not coming back. There is a small percentage of men that remain castrate sensitive for extended years and some never become castrate resistant.