The Scandinavian trial that compared surgery to no surgery is one of the very few randomized clinical trial of treatment of prostate cancer. It is level 1 evidence that show that surgery can work, but it's not as effective as you might think. I saw that the article and the graphs from the most recent report of this study, with 12 years of followup, is now posted for free on the pubmed website. It's worth looking at these.
There is a recent thread here about
longevity with prostate cancer. This is the best article I've seen to answer that, because if you ask the question, "will surgery help me to live longer", the next question is "compared to what?". The answer that you want to this second question is, "compared to those who didn't have surgery". This study gives some of the answers to these questions. It was helpful to me when I was deciding on whether to get treated:
The link to the charts:www.ncbi.nlm.nih.gov/images?term=18695132[PMID]
Especially look at Figure 3. In this patient group, surgery increased survival if it was done on men younger than 65. When it was done on older men, there was no difference in survival between surgery and watchful waiting.