I have done a post similiar to this in the past, but the issue keeps coming up in patients I talk to and I felt it was worthwhile to revisit.
As simplistic as this drawing is, it answers a question and a very common misconception by many patients. As a surgeon I have to diligent to make the following point very clear. All of the cancer in the prostate is removed at the time of a prostatectomy whether it be open or robotic. If however cells of prostate cancer have extended beyond the prostate before the surgery either by local spread through the capsule of the prostate or in the blood stream or lymphatics, then removing the prostate will not cure one of prostate cancer.
This is important because many patients mistakenly elect to have a prostatectomy for the “cure factor” as a given. If you want to try to predict the chances that your cancer is not “totally contained” study the “Partin tables.” Plug in the specifics of your disease that is known from your PSA and biopsy and rectal exam and it will give a “prediction” of the likelihood that there is extracapsular spread before surgery. This prediction also answers the question about, “What are the chances that if I remove my prostate that I will need to have radiation after that?”
The point is that surgery does not assure cure. Then the issue of the need for post surgical radiation and pre surgical local extension is one in the same.