When I was in your position I asked to have the various treatment options and likely outcomes explained to me. I was given links to the NCCN Guidelines and recent studies supporting each of the treatment options available for someone my age in a similar physical condition/life expectancy having the same NCCN category/Gleason score and confounding risk factors (IDC, Cribriform, EPE and .52 Decipher score, in your case). This made it possible to evaluate, for each treatment option, the median time to biochemical recurrence, cancer specific mortality and overall survival data. I could then weigh potential short term side effects during and/or after each treatment option and compare it to life without short term side effects due to treatment, but a much shorter time to the side effects which would likely result from untreated biochemical recurrence or the treatment of biochemical recurrence.

I walked in your shoes nearly 4 years ago when diagnosed with Gleason 9, EPE and cribriform. It was a frightening time to have to reach decisions that would dictate the quality, potentially both short and long term, and duration of life. The multidiciplinary team of doctors I met with at Fred Hutch/UW in Seattle provided the studies, data and links I needed to reach my decision to have RT (I chose to have proton) with 2 years of lupron + abiraterone. I had side effects many of which lasted approximately a year after completing ADT, but they certainly weren't debilitating. I continued to work as a contractor and we hiked, xc skied, mountain biked and kayaked with friends through the two years of treatment, although somewhat less frequently.

In the absence of comorbidities that would complicate your treatment decision, I hope that you have the data the doctor used to reach the conclusion that "the probable side effects and not worth the potential benefits." It is your body, your life and your choice. I hope you will continue to post so we can all continue to learn from and support each other. Wishing you continued success and happiness on your PCa journey!
Bill