Results of a new study also show the majority have the procedure at smaller hospitals, where complications tend to be higher.
There are many unknowns from the findings published in the "British Journal of Urology International." It's not clear why men 75 and older are having the surgery at smaller non-academic hospitals.
For elderly men, the risk of surgery is usually thought to outweigh any potential benefit.
Researchers are questioning whether some of those in the study may have been over-treated.