Your chance of cure from prostate cancer after surgery depends upon the type of disease you have, and apparent confinement of disease to the gland. The relevant factors include: Gleason’s Score, capsular penetration, seminal vesicle involvement, margin positivity, lymph node involvement, and the preoperative and postoperative PSA levels. The Kattan nomograms may be used to calculate your chances of cure after surgery.
Many of these factors are already set at the time of diagnosis. The one thing you and your surgeon may have some control over is establishing negative surgical margins (no tumor at the cut edge of the prostate specimen). Patients with negative surgical margins have better chances of long-term cancer cure than patients with tumor identified at the margins. How could you possibly have any control over this, you ask? The answer is in the type of operation you choose for yourself! This question is bigger than robotic vs. open. It’s about how wide of a resection you agree to have done.
The chance that your cancer is confined to the gland at the time of surgery has been well mapped out in Partin’s tables. Prostate cancer, however, when it escapes the capsule of the gland, sprinkles itself in the area right outside the prostate where the nerve bundles live. Certain low-risk prostate cancers demonstrate little chance of spread beyond the confines of the gland into the area of the nerve bundles, and it makes sense for someone who is sexually active to undergo nerve sparing surgery to preserve potency. Others with high-risk prostate cancers have a high chance of spread to the area of the nerve bundles, and sparing the nerves for these patients greatly increases the risk of leaving cancer behind.
Thus, there are two possible reasons for being labeled margin positive postop: 1) biological extension of disease beyond the confines of what could be safely resected, or 2) inadequately wide surgical resection. You must review your risk of disease spread with your operating surgeon preop to make a plan for how wide a resection to make. Even for patients with palpable disease (a bump that can be felt on rectal exam), the cancer cells are microscopic, and the decision to spare nerves or make a wide resection is primarily made before entering the operating room. On occasion, there are gross findings discovered at the time of surgery which compels the operating surgeon to cut more widely than planned preop, but this is rare. The use of preoperative MRI is sometimes useful to decide whether or not to preserve the nerves or cut widely.
Robotic surgery, because of greater magnification and the essentially bloodless field of view, allows for better chances of achieving proper negative margins. It also allows for better chances of sparing nerves for purposes of preserving postoperative potency and sexual function, when intended. Dr. Kaynan thoroughly reviews with his patients these issues and helps his patients choose the right balance – you want to maximize the chances of cancer control without unnecessarily sacrificing potency and sexual function. Again, the surgeon you choose to help you make the right plan, and execute that plan, is just as important as the kind of treatment you choose.