As far as I know there are no real studies which have examined this.
First of all, long term studies such as this one are virtually impossible to conduct.
You would have to recruit a cohort of BBers who admit they are on juice (most claim they are "clean") they you would have to follow them over several years, administering tests along the way. The drop out rate would be higher than Cormier in high school.
Thirdly, there would be NO ONE willing to fund this type of a study and lastly no paper which would accept this type of article.
Therefore, for the above reasons this answer will never be answered definitively. Everything else on this post is pure conjecture based on a few isolated cases of those people who died, got very sick or are perfectly fine.
However, there are tons of confounding factors in group analyzing individual cases such as these....genetics, age, duration of AAS, Dosing, Types, other supplements etc....
Having said all this, as one of the MD's on this board, I would have to say that you would be hard pressed to find an accredited physician who would endorse taking AAS.