Two things strike me about this article - Prof Emberton says 50% of men are currently left with ED following treatment, which is a far higher statistic than the hospitals usually own up to, and there are 100,000 biopsies each year and 40,000 diagnosed so 60% of men undergoing biopsy get the all clear.
Begs the question, why is ED a shock for some men? Not enough is done at those pre-surgical appointments to make sure men and their partners understand how likely it is that they will have problems afterwards.