IMHO, for this kind of thing, you have to look at it with a rigorous eye.

Anecdotes and "common sense" are all nice, but the only way to know if there is a relationship (let alone a causal one) between cycling and prostate issues is to accumulate information from a large data sample, try to eliminate special cases, and determine whether the statistics justify the conclusion that there is any relationship.

Then, you have to determine if the relationship is correlative or causal.

So IMHO the only real value in asking the question here is to ask if anyone else has discovered a study suggesting a relationship (especially a causal relationship) between cycling and prostate issues.

To my knowledge, there is none. If there are any, I'd love to read them!

But anecdotes are fun, so here is mine. I get yearly PSA and digital exams, and all is normal. My neighbor up the street is the same age, doesn't cycle, and has had several biopsies of suspicious lesions. That doesn't mean squat, of course.