Have you been told for definite that you have prostate cancer? Do you know how potentially aggressive it is i.e. the Gleason Score?
From what you say, if "they" (urologist / oncologist) are recommending treatment, what treatments are they recommending?
If the cancer is contained within the prostate, as yours seems to be, i.e. it is localised, then there are a variety of treatments available, all of which offer a cure. You can find out more about each treatment and their side effects by requesting / downloading the toolkit from this website.
You'll find that there are many variables to consider and what might have been right for me, may not be right for you.
Therefore, take your time in reading up about each treatment before choosing which one / combination to have.