The best answer needs to consider your condition and the recommendations of doctors. I am currently in this decision process as I was diagnose the day after Christmas with Prostate Cancer, I’m only 52 with Gleason 6 and a PSA of 7.1
My first step was to spend some time with my wife and in prayer to reflect on my Primary Objectives and Priorities in Life. My Three goals were Longevity to support my wife and children and to be around to see daughters grow up and get married and grow old with my wife; Quality of Life and Avoiding Risk such as complication in Surgery and because of my personal condition PE (blood clots), Cerebral hemorrhage and other risks with any major surgery. The priorities for quality of Life, for me start with avoiding impotence, limited incontinence and other side effects.
Because of my youth, most books and some doctors recommend the Radical Prostatectomy as it has the greatest probability of no recurrence, but the greatest risk of complications, which increase due to my weight and history of a PE. Although the risk may be small, I have removed Radical Prostatectomy from my list of treatment and I am currently looking into the options of Radiation Oncology.
You will need to determien what is most important to you and how your age and health effect the decision. Once you are 65, I would look hard at the other options.
Good Luck and God Bless