I don't think there should be any arbitrary limit for surgery - everybody is different. There are men who are super healthy at 70, very active and fit and on the other hand there are 50 year old patients that are overweight, have diabetes, high BP and live sedentary lives. How is 69 different than 70 ???

BOTH methods have pros and cons and one should choose the one that is the most promising for good results and possible long term remission.

Both methods can cause incontinence and ED, and radiation can cause problems with chronic proctitis, secondary cancers, strictures, scar tissue, cystitis etc.

Unfortunately neither method is walk in the park. What will one choose should be first and foremost determined by type and grade of cancer. If there is no difference in possible outcome than patient can choose but with understanding that both can have negative side effects .

It is also very important to know that results will greatly be influenced by experience and expertise of surgeon and radiologist.

There is one more very important factor IMHO - the fact that one can have radiation after RP if needed, but one can not have radiation twice for the same area. Also, RP is the only way to actually examine prostate and see in detail what is going on and if there is a possible breach of cancer outside of a gland. During RP doctor can also harvest some of the lymph nodes and examine them for metastasis and according to findings adjust further treatment course.

Bottom line - there are so many factors that need to be considered and it is not just matter of simple "preference" or just "age".