If castrate resistant and high Gleason which is the time to metastasis one can expect? Does it vary if the main tumour was operated or radiated?
If not castrate resistant but also not on any treatment, high Gleason and tumour already outside the capsule, would metastasis come much earlier than after CRPC?
It would help if you were more clear about your particular situation. If you're asking what is the median time to first metastasis detected by a bone scan/ct after biochemical recurrence following radical treatment, it is about 8 years.
Particular situation: Gleason 9 (mostly 4+3, but 1 4+5), PSA 35, extracapsular seminal vesicle involvement, PSMA PET CT does not show clearly if bone mets (already 3 done), but probably little spots pelvis region, low burden, diagnosed 1,5 years ago, no standard treatment yet.
The question would be if radiation to principal tumour could retard mets.
And if there is an idea of progression doing nothing.
ADT would be a temporary solution (that would be done anyway if doing radiation).
Till now there does not seem too much progression, besides local activity, PSA rose from 17.5 to 35.6 in 1.5 years (with lots of ups and downs). Bone AP high normal range.
You are progressing, albeit slowly. Progression is always slow at first - exponential growth starts slowly. If you have few mets, radiation of the prostate may increase survival, STAMPEDE found. If there are no mets yet, radiation of the prostate (+ pelvic LNs) may cure you.
Your comment about initial slow growth and exponential growth later catalyzed something that I studied a long time in my youth - autocatalytic processes. I believe PCa growth rates (untreated) could be fitted to equations that characterize autocatalytic growth. Cheers, Phil
Liver/lung metastasis and carboplatin
Lymph node Metastasis 
Insufficiency fracture as a sign of metastasis
Growing bone metastasis with a psa of 0.03
Metastasis to lung?
