Prostate problems have been associated with cycling but Urologists do not agree that cycing causes or contributes to the problem. My doctor told me to ride my bikes because exercise is good for prostate problems. There's a Urologist who posts over on the Road Bike forum who has posted that riding bikes does not cause prostatitus.
As for the Biopsy, I didn't feel a thing, until the pain medication wore off. Then I had soreness. No big deal.