Advances in kidney cancer deal much more in surgery, rather than treatment options, according to Alexander Kutikov, MD, FACS.
Kutikov, an associate professor of Urologic Oncology, Fox Chase Cancer Center, says that while surgery is generally viewed unfavorably in most other cancer types, surgery is the best curative method for kidney cancer currently.
In an interview withTargeted Oncology, Kutikov outlines how medical professionals should approach surgery with their patients, who to perform surgery on, and how robotics could help surgery sometime in the near future.
What is the current state of surgery in kidney cancer?
The state of surgery in kidney cancer today is quite complex. Kidney cancer remains to be an incredibly surgical disease really, a chance to operate on a patient is a chance to cure them. There is this concept in the field of treatment disconnect. Administrative data sets tell us that although we're doing more surgery, the mortality rates for kidney cancer still appear to be rising. Our group is working to show that that treatment disconnect phenomena is not as profound as we had thought. If you control for missing data and you control for missing incidents, you can actually show that the affect is quite attenuated.
Most of us in kidney cancer, especially in localized kidney cancer, believe that we are moving the needle on helping stop progression in kidney cancer for those who have localized disease.
When one faces a kidney cancer patient, I think there are four questions to be asked. Those are if you do the surgery, what kind of surgery to do, whether partial or radical, what technique to use, and what to do after surgery and how to follow that patient. With regard as to whether to take the patient to surgery, its arguable that the decision to go to surgery trumps just incision. That's the critical piece and that decision-making is becoming more and more sophisticated.
Most of us believe that patients with tumors that are less than 3cm that show zero order or really sluggish growth kinetics are really good candidates for active surveillance because they're motivated to monitor their tumors. This is especially relevant in older patients or patients with comorbidities. There was an important paper published this year from Johns Hopkins University, Columbia, and Beth Israel Deaconess where they created a multi-institutional prospective registry that compiled patients undergoing active surveillance, and I think we're going to learn a lot from that data.
How do you make the decision on when to take a patient to surgery?
With regard to taking a patient to surgery and making that decision, our group has shown over the years and really pushed the concept of "don't make that decision in a vacuum." You need to integrate the competing risk of death into that decision making. We've published predictive tools to quantitate that decision using nomograms and other point-of-care tools to help clinicians who are in the trenches to make that decision, and at least give them a point of discussion and a way to contextualize their conversation with the patient.
What's really getting traction in the clinical space is the use of renal biopsy. In many cases, it helps to determine if a patient who is elderly or frail is a candidate for surgery. Renal biopsy is excellent at separating the sharks from the minnows when determining if a mass is cancerous or benign. So a patient who is at a significant risk for surgery could be a candidate for renal biopsy, which is incredibly helpful. More and more biopsies are being done now.
A paper from John Leppert [MD] of Stanford [University] showed that approximately under 30% of tumors that are resected undergo renal biopsy, which is an uptick from the past. What the renal biopsy is not great at is differentiating between high- and low-grade tumors. It can't tell those apart, so there are a lot of people in this space that are working to improve that characteristic of the biopsy.
Are these biopsies helpful?
There is a big debate in the field as to if one should do a biopsy on all-comers. I strongly feel that we're not quite there yet. For my elderly patients who who are candidates for active surveillance patient, I'm not sure a biopsy is helpful. Also, our data with regard to follow-up of benign masses is just not robust enough for me to not treat a young, healthy patient with a benign mass and follow them long-term. Again, we're just not quite there.
Are there different methods of surgery for these patients?
Whether we do a partial or radical nephrectomy is an important question to consider and to present to the patient. There is no question that for masses less than 4cm that are anatomically simple, partial nephrectomy is absolutely the clinical standard. The question arises for a mass that’s bigger and more anatomically complex, especially in a patient with a normal contralateral kidney. Is this patient a candidate for a partial or a radical nephrectomy?
Partial nephrectomy is usually associated with a higher risk than radical, and really those risks are perioperative risks that are double in partial nephrectomy for complex tumors. Many of us also think that the oncologic safety of partial nephrectomy for larger masses does not have enough data to be backed up right now. In these larger tumors, it's a real clinical struggle to know what to do. Our enthusiasm for partial nephrectomy is fueled by institutional and retrospective data sets that show us that there is a partial overall survival benefit to partial nephrectomy.
In this environment where there's a little bit of uncertainty, we know there is a high risk for a partial nephrectomy versus the potential benefits, and the time is really right for a randomized trial. I would love to see our field come together and put a trial together.
With regard to how to remove the tumor, there is a lot of work in that space. Robotics are here to stay, and at Fox Chase Cancer Center where I work, about a third of all robotic partials are now done retroperitoneoscopically. You can offer minimally-invasive surgery, and that's a very powerful tool in a kidney surgeon's armamentarium.
The urologic literature is peppered with a lot of debate on how wide your margin needs to be. Working with our colleagues at the University of Florence, about a year ago we developed an objective scoring system on how to document and report and communicate resection techniques. We just finished collecting data from over 500 patients from 16 institutions from across the US and Europe, and that data are being compiled and analyzed. What I can tell you is that enucleation, which is just peeling off the tumor at the base, is much more common than we previously thought even at institutions here, which don't promote enucleation as a resection technique. So really, just understanding how and what margin we resect the tumors is important in answering these oncologic safety questions, and better understanding partial nephrectomy.
Do you see the field moving away from surgery?