At the 2024 SIR Annual Meeting, AJ Gunn, MD, University of Alabama at Birmingham, discussed how to best treat patients with central renal tumors.

Dr Gunn highlights how central renal tumors can be more complicated than peripheral tumors, the options for treatment of these tumors, and the potential complications that can arise.

Transcript:

AJ Gunn: My name is AJ Gunn. I'm the Vice Chair for interventional affairs and the division director for interventional radiology at the University of Alabama at Birmingham.

Oncology Learning Network (OLN): How does treatment differ for central renal cell carcinoma tumors?

Dr Gunn: For a long time we've known that central tumors are more difficult to treat than peripheral tumors in the kidney. If you look back even at the earliest descriptions of percutaneous renal ablation, having a central versus a non-central tumor led to increased rates of complications and increased rates of recurrence. Despite our improvements in technology and increased experience with this, those central tumors that are close to the renal collecting system still tend to pose a problem both for complications and recurrence rates.

OLN: What are the interventional treatment options for this disease?

Dr Gunn: The primary treatment option for patients that have small renal masses, patients that have tumors less than 4 cm in size, there are really 2 coequal treatments. One is partial nephrectomy, where they take out a portion of the kidney, and the other is percutaneous ablation, where we freeze or burn a portion of the kidney.

The outcomes of those 2 treatments are very similar in the sense of overall survival, and cancer-specific survival, although percutaneous ablation does a better job at preserving renal function. We keep people at the hospital shorter, it’s shorter than surgical treatments, and our complication rates are a little bit less than they are with surgery.

Surgery, as far as local recurrence, is 1 to 2 percentage points better than ablation, as far as local recurrence. But especially when we're considering patients with central tumors, a lot of times the urologists aren't able to do a partial nephrectomy and a lot of the patients that I see, especially with borderline larger central tumors, they're coming because the option that they were provided by urology was a total nephrectomy, losing all of their kidneys. They're willing to undergo a more minimally invasive treatment and just to preserve whatever part of the kidney that they can. That’s where I really see, with central tumors, the comparator between a surgical treatment and an interventional radiology treatment is, especially when the only option surgically is not a partial nephrectomy but is a total nephrectomy. And then pursuing something that's more minimally invasive definitely makes sense in those scenarios.

OLN: What are the factors to consider when deciding on treatment for a central renal cell carcinoma tumor.

Dr Gunn: There's 3 things. Number one, size, that we've talked about. Number two: is it central? Is it non-central? I think that's probably the other biggest thing that leads either to complications or to recurrence rates. Can they, along those lines like we discussed, can they do a partial nephrectomy or is it only a radical nephrectomy?

And then the last thing I would say is patient-specific factors. And by that, a couple things: One, are they a surgical candidate or not a surgical candidate. Some people with increasing medical comorbidities that we're seeing in our patients, they're just not able to go to the operating room for one reason or the other. The other side of that coin is there are a sizable number of patients that don't want to go to the operating room. They don't want to have surgery anyway.  If they're not willing or they're unable to go to surgery, that really leans somebody more to getting an ablation procedure rather than a surgical procedure.

OLN: What are the most common complications that can arise with ablation in this patient population?

Dr Gunn: For renal ablation overall, you're looking at about 4% to 5% major adverse event rate, which means they have a complication that we have to do something about. As opposed to some sort of minor complication that happened, but nobody had to treat anything. That’s less relevant. In that class, bleeding is by far and away the most common complication. And if it's a central tumors or larger tumor, all of those have higher rates of bleeding than peripheral tumors or smaller tumors. It's about 3% overall for major hemorrhagic event rate, which either means we have to embolize the bleeding area or we have to give a blood transfusion.

Other things are much less common or in that 1%, less than 1% ballpark. And there you're talking about injury to the renal collecting system, like a urine leak or urinary obstruction, injury to some adjacent structure that's nearby, like a nerve or the small bowel or the colon, pneumothorax, some sort of injury to the lung as well, injury to the kidney itself where it hurts the renal function so much that they have to start dialysis or start seeing an nephrologist.

Bleeding by far and away is the most common thing. Apart from that, everything else is kind of in that 1 or less percent ballpark.

OLN: How important is kind of the multidisciplinary approach for this patient population?

Dr Gunn: When you're treating any kind of cancer, not just renal cell carcinoma using a multidisciplinary approach— And people can use that term and just because that makes it sound nice. But I've really found, especially here at UAB, we have a very collaborative approach to how we treat our patients. We have a tumor board every week that happens on Mondays, and at UAB, outside of that, I'll get messages from a medical oncologist, asking "Hey, here's this area of metastatic disease," and he'll copy both me and the radiation oncologist and say, "Hey, what do you guys think about this?" And we have a mini-tumor board as we go across there. When we're all working together and create a good system for the disease process, then it's going to draw patients into the system.

We've never seen it as, “Oh my gosh, I did 75 ablations last year and this year I did 68. The push and pull of that. It's about creating a good referral pattern for everybody in this pathway. We have these conversations all the time and when you do that, and people see you as a good partner, you're not trying to grab every single case. There’s certainly people who come to see me and I say, "If I were you, I would get this cut out of me, because of your age, location." And sometimes patients say, "I don't want that no matter what.” And that's fine, we can pursue that.

But it's a two-way street. It's not everybody comes to me and therefore they're going to get an ablation. The great thing is I love is when my urologists send me patients who are just want to hear about it. My urologists feel like they can talk about it, and I trust them to do that very well, but we'll get a couple of patients every week who just want to hear their options. They do a better job explaining the surgery portion of it, I do a better job potentially of explaining the ablation portion of it. Just hearing their options from someone who actually does that case every day is really helpful as well.

I think that that's a huge benefit of treating all cancer patients and kind of multidisciplinary teams, because you don't get lost in your own silo of “this is what I have, so this is what I'm going to do.” There are other options out there from other specialties.

OLN: Do you anticipate any shifts in the treatment paradigm in the near future?

Dr Gunn: There are things that are moving under the surface. We just had a big update to the NCCN guidelines for percutaneous ablation last year. There was this caveat for smaller tumors that you should counsel patients above 3 cm for higher rates of complications and recurrence. We took that comment out of there. I feel like we can do things very successfully, anything under 4 cm in size. For larger tumors greater than 4 cm in size, we added in a comment that we should consider percutaneous ablation and non-surgical candidates, which wasn't there before. I think that that's really great.

The other thing too is the incidence or the number of people that have renal cell carcinoma continues to rise, but the number of deaths from renal cell carcinoma is about the same. Who are the patients that we should be treating vs not be treating? There’s a decent number of patients who could benefit from just watching. We have a decent number of patients here at UAB that are just under active surveillance. That’s the other thing, patient selection. Can we get better at that, other than just sitting and watching them and seeing what happens.

Those are the biggest shifts that have happened in the last little bit.

OLN: What is the final key takeaway of your session?

Dr Gunn: When we're talking about central renal tumors, I think the key takeaway is that they're more complex than peripheral tumors. They certainly lead to increased rates of complications potentially and increased rates of local recurrence. But with proper planning and patient selection, they can still be treated really effectively. That's probably the big takeaway.

For my specific talk in this session, what are some of the strategies we can use to make sure that we do this as safely as possible. Knowing the challenges, helping people to understand the challenges that it presents. Also providing some solutions on the back end for those challenges.