Welcome to PracticeUpdate! We hope you are enjoying access to a selection of our top-read and most recent articles. Please register today for a free account and gain full access to all of our expert-selected content.
Already Have An Account? Log in Now
Optimizing Staging in Bladder Cancer
Dr. Mossanen: Hi. Welcome to PracticeUpdate. I am Matt Mossanen, and I am lucky enough to be joined by Dr. Adam Kibel. Today we’re going to talk about bladder cancer. Dr. Kibel, I thought it might be useful to go over some of the strategies that you use when you're trying to optimize staging for patients that have high-risk non–muscle-invasive bladder cancer.
Dr. Kibel: Well. I think that central is a good TUR. You want to ensure that you've actually got muscle in your specimen and documented that it is not actually T2, T3, or T4 disease. And so, you do an initial TUR, it comes back as high-grade T1, you need to take the patient back for a repeat resection in order to ensure that you didn’t miss any cancer. If there’s no muscle in the space of the specimen, it’s quite high that there’s actually muscle invasive upwards of 50%, but even if there is muscle in the specimen, about 15% of the time it’s actually T2. So, I cannot overemphasize that; it’s in all of the guidelines. It really is the standard of care in 2020. Layered in there is also getting an MRI. I think this is one of the spaces that MRI can be very useful. Part of the problem is you do a resection and the abnormalities exist, and then it’s hard to tell whether it’s invading the muscle or not. So if you're looking at a tumor that you're going to take to the operating room and you're sort of on the fence, is this invasive, is it not invasive, I feel it’s a good idea to get a good MRI with gadolinium before you do the resection, before you've disturbed any tissue planes.
Dr. Mossanen: Is there a specific amount of time that you like to wait if you've done your first TUR and you were thinking about an MRI?
Dr. Kibel: That’s a difficult question. The problem is, is those changes can exist for months and you can't wait months in order to manage somebody that you're concerned that has invasive disease. I think we’re fortunate that in most cases when you look in the bladder, urologists are remarkably good at saying yeah, this is a bad tumor, maybe this isn’t such a bad tumor, and I think we’re pretty good at choosing the right patient to get an MRI in beforehand.
Dr. Mossanen: It is definitely a challenge figuring out when to get the MRI after the initial TUR. Some of the suggestions are to wait around a month at least, but as you said, some of the TUR changes can really linger for much longer than that, and so relying solely on radiographic staging is not something that we do.
Dr. Kibel: I don't think it’s useful. I shouldn't say that. I think it is useful in the right patient, okay, but you can't just have a blanket statement that you need to get this imaging and everybody. It’s somebody you pick and choose, somebody who you think could have muscle-invasive disease but you're not sure. I mean, clearly the person with a big bulky tumor, they’re not necessarily going to benefit from it. If you want to get it after a TUR, you're probably getting the same information. You're mostly interested is it growing into fat, and is it resectable, and are the lymph nodes…and by resectable I don't mean the TUR resectable I mean that you can remove the bladder…and are the lymph nodes involved, whereas I’m more talking right now much more subtle. You have a tumor that looks a little ugly. You're concerned it could be invading the muscle, but you're not sure. I like the month. I mean, the month is when you're going to take the patient back for the repeat TUR, and so if you wait more than a month then it gets reset again. But I would just warn people that the false-positive rate is probably a little higher in somebody who’s had a TUR within the past month or two.
Dr. Mossanen: Well said. It’s just a nice additional tool to have when you're trying to sort out these patients.
Dr. Kibel: Correct.
Dr. Mossanen: For those patients that, let’s say, do go on to be diagnosed with muscle-invasive disease, it’s important to then do full staging, and so a PET CT is often employed in bladder cancer, and I was wondering if you could talk a little bit about some of the advantages or maybe some of the limitations with using PET CT when you are getting it for those patients.
Dr. Kibel: Right. So, I don't think you have to get a PET CT. I’d say conventional imaging works pretty well. Patients, generally, if they have metastatic disease, have enlarged lymph nodes, that’s really what we’re worried about. We all know that bone scan clearly has its…conventional bone scan clearly has its shortcomings. It’s unfortunately where we’ve been…the cards we’ve been dealt for the past 50 years. The PET scan…I became interested in PET scanning back in the, I guess, 2000s, right after the turn of the new millennium when all of these patients were showing up with PET scans, and I just thought it was crazy. So I went ahead and did a study where we took patients who had negative CTs, negative bone scans, and then we got a PET scan beforehand, and then—this is before neoadjuvant chemotherapy had really taken off—and then we do surgery on them, irrespective of what the PET scan showed. We found about 20% of the patients actually had a metastatic disease that was not detectable by conventional imaging, and that made me really rethink it.
I think one of the advantages of the PET scan, beyond detecting cancer that you can’t detect with standard imaging, there’s also the advantage that you get a good look at the lungs, which you…much better than I would even argue with chest CT, because metastatic disease will light up, and let’s face it, almost everybody’s lungs are riddled with small indeterminant lesions that can make the interpretation of a chest CT difficult.
Dr. Mossanen: I think one of the advantages of the PET CT early on, for patients that then go on to cystectomy, is you have that baseline scan, so when their surveillance is happening and it is a question of a lesion you can often compare to what was done before the cystectomy. But as you said, it’s not something that must be done in all patients, but I think recognizing for high-risk non–muscle-invasive bladder cancer, the repeat TURBT, and the possibility of MRI being a useful adjunct, and then thinking about a PET CT as a way to get maybe a little bit more accurate staging is helpful for anybody working in that space.
Dr. Kibel: Oh, absolutely, and particularly as you're contemplating giving these patients chemotherapy prior to surgery, or even if you're contemplating not giving chemotherapy prior to the surgery. If you're on the fence, this can be the kind of test that tips you in one direction or the other.
Dr. Mossanen: Well said. Well, thank you very much for taking the time to chat with us, and thank you very much for watching.
Additional Info
Disclosure statements are available on the authors' profiles: