There's been a new study from MSKCC that confirms what I wrote:
/pcnrv.blogspot.com/2017/08/the-myth-that-younger-men-should-not.htmlGiven his history, I don't think he really needs annual biopsies anymore as long as his confirmatory biopsy showed the same thing. If that's the case, then he clearly has the insignificant, indolent kind. I can't guarantee that kind will never grow, but it's pretty certain that if it progresses, it will do so very slowly for a long while. So, maybe another mpMRI in a couple of years, and if it is still PIRADS 2, wait maybe 4 years for the next one, etc. There are no hard and fast rules, just judgment and a matter of his comfort. So all he may really need from Moffitt is the occasional mpMRI. You can get biannual PSAs done locally and unless something is looks awry, you can just call it in.
PC aggressiveness goes up with age. Yes, there are occasional cases, some on HW, where young men get unusually aggressive subtypes, but that is the exception rather than the rule.