Gaurav Syal, MD, on Dysplasia Surveillance in 2020
In this podcast, Gaurav Syal, MD, talks about his session at our Advances in Inflammatory Bowel Disease regional meeting in Los Angeles, during which he will speak about the importance of dysplasia surveillance and how dysplasia should be tracked in the future.
- Syal G. Dysplasia surveillance in 2020: What should we be doing? Talk presented at: Advances in Inflammatory Bowel Disease Regionals; August 22, 2020; virtual. https://www.eventscribe.com/2020/AIBDregionals/agenda.asp?pfp=FullSchedule.
Gaurav Syal, MD, is an assistant professor of medicine and a gastroenterologist with a focus on IBD at Cedars Sinai Medical Center in Los Angeles, California.
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Amanda Balbi: Hello, everyone. Welcome to another installment of Podcast360, your go‑to resource for medical news and clinical updates. I'm your moderator, Amanda Balbi, with Consultant360 Specialty Network.
Today, I'm speaking with one of the speakers at our upcoming Advances in Inflammatory Bowel Disease meeting, Dr Gaurav Syal, who is an assistant professor of medicine and a gastroenterologist with a focus on IBD at Cedars‑Sinai Medical Center in Los Angeles, California.
His session is titled “Dysplasia Surveillance in 2020: What Should We Be Doing?” Let's dive in.
To start, can you give us an overview of your session? What should gastroenterologists know about dysplasia surveillance in 2020?
Gaurav Syal: As far as the overview of the session is concerned, I will be talking about the risk of dysplasia and IBD, which we know that is increased. We'll be touching on some recent data about the risk of dysplasia in the era of effective treatment that we have currently.
We'll also be talking about the risk factors for dysplasia development in patients with IBD. We'll be touching upon the different surveillance modalities in patients with IBD and which ones should we be using in 2020. Finally, we'll be talking about when you detect the dysplasia on a surveillance colonoscopy, what should you do?
Amanda Balbi: Let's go a little bit deeper. You said that you are going to talk about the surveillance modalities. What kind of surveillance modalities do we have, and how do you foresee them being used in 2020?
Gaurav Syal: In 2020, almost everybody is using high‑definition colonoscopes, so I don't think we need to talk about the standard‑def colonoscopes, which were used a long time ago. A lot of research used those to compare the current modalities.
The modalities that we practically have at this time are the high‑definition white‑light colonoscopy. The second one would be high‑definition white‑light colonoscopy with the addition of narrow‑band imaging, which is a proprietary of Olympus and is commonly used. The third one is high‑definition with chromoendoscopy. These are 3 that are available and have some research regarding which one is effective.
As far as which one should we be doing, in the last 10 years or so, there have been several randomized controlled trials, which is the highest degree of evidence we seek in medicine comparing these 3 modalities. To summarize it, the high‑definition white‑light endoscopy by itself compared with chromoendoscopy, the randomized trials suggest that there perhaps is not a significant benefit to using chromoendoscopy over high‑definition white‑light endoscopy. Previously, the nonrandomized studies had suggested that there may be benefit in chromoendoscopy over the high‑definition white‑light endoscopy, but in the randomized trials, it hasn't panned out.
As far as the NBI uses is concerned, there have been a couple of randomized trials comparing chromoendoscopy and NBI. They suggest that both are equivalent. In essence, if we look at the strict evidence, there is no one modality which is the best.
If you keep in mind that there is still some nonrandomized evidence from the past, which suggests chromoendoscopy may be better. If you have the expertise and the availability, then using chromoendoscopy or NBI may have slight benefit over just using high‑definition white‑light colonoscopy.
The most important thing is to do a good examination, spend time looking at the colon and trying to find subtle lesions. If somebody doesn't have the availability of NBI or chromoendoscopy, that by itself should be sufficient.
Amanda Balbi: Let's talk a little bit more about why dysplasia surveillance is important in 2020.
Gaurav Syal: It's been long known that patients who have ulcerative colitis, which extends beyond the rectum—either people who have left‑sided colitis or extensive colitis are at increased risk of dysplasia and colon cancer development. Similarly, there is also data that people who have Crohn disease involving the colon, especially when it's involving more than 30% to 50% of their colon, also have a similarly increased risk of dysplasia.
Recent data suggests that the older data probably over‑estimated the risk. The risk is still thought to be one-and-a-half to two times higher than age- and sex-standardized risk of colon cancer, but the risk is much smaller than it was previously thought.
Based on the recent data, both from Europe and from the United States, the risk is still increased. That's why we still need to continue the dysplasia surveillance in 2020.
Amanda Balbi: Interesting. Why do think that the risk was previously overestimated?
Gaurav Syal: A lot of that has to do with the use of effective medical therapies that were not available at that time. Now, in the era of biologic therapy, we are able to get people to not only clinical remission but a lot of people to endoscopic remission and some people to even histologic remission.
Recent data also suggests that the visible inflammation or macroscopic inflammation, and histologic inflammation is associated with an increased risk of colon cancer. With the use of better medical treatment, we are able to bring down the inflammation better. As a result, now, we are seeing a much lower risk of dysplasia than it was previously thought.
Amanda Balbi: That's great. Do you think biologics played a role in that?
Gaurav Syal: Yeah, I definitely think so. There was data previously suggesting that people who were on methylamines had a lower risk of developing cancer. Then there was a study from France, from the CESAME cohort, which suggested that people who were on thiopurines also had a lower risk of dysplasia development in the long term.
We know that the biologics are more effective than both methylamine and thiopurine. Even though there are no direct studies correlating biologics with the recent decrease in the risk of cancer, it's pretty clear that the effectiveness of biologics has a lot to do with driving down the risk of dysplasia.
Amanda Balbi: Awesome. That's great. Moving on, what else should gastroenterologists know about your session?
Gaurav Syal: As I initially said, patients with IBD, with ulcerative colitis, who have disease extending beyond the rectum and with Crohn disease who have more than 30% to 50% of their colon involved should undergo dysplasia surveillance after having the IBD diagnosis for 8 years or longer.
As far as the surveillance modalities, NBI or chromoendoscopy may have a slight edge over high‑definition white‑light colonoscopy alone. In the absence of those, a good exam with high‑definition white‑light endoscopy is going to be sufficient in most cases. That's one.
The other important thing is that dysplasia surveillance intervals should be individualized based on patients' risk factors. Various risk factors for development of dysplasia include the extent of disease. People with colitis who have more-extensive disease of pan‑colitis have the highest risk. Those who have active inflammation have a higher risk than those who have quiescent disease. Patients who have PSC appear to be at a pretty high risk. Those who have family history, especially with the first‑degree relative being diagnosed with colon cancer, have a higher risk.
Presence of certain anatomical abnormalities, like development of strictures or extensive pseudopolyps, these factors do increase the risk of colon cancer. We should keep these factors in mind when we talk to patients about how frequently we should survey their colon for dysplasia. Typically, recommended interval is between 1 to 3 years. Again, it could be 1 year in patients who have multiple risk factors or have PSC, or it could be 3 years in patients who have left‑sided disease and generally have quiescent colitis. That's the second.
The third I already touched upon would be that PSC patients should start the dysplasia surveillance at the time of their IBD diagnosis and subsequently should have annual surveillance colonoscopies.
The next one will be the role of random biopsies, which were previously recommended by all guidelines. More recent literature suggests that the role of random biopsies is unclear in a way that the yield of random biopsies seems to be fairly low.
We don't know whether random biopsies are still important in the era of advanced endoscopic techniques like high‑definition scopes and NBI and chromoendoscopy. Most of the guidelines are not recommending using the random biopsies at this point but are also not recommending necessarily against them.
Another very important point is that most of the dysplastic lesions that are found in patients with long‑standing IBD are visible. There are several studies that suggest that over 90% of the lesions can be seen with the improved endoscopic imaging modalities that we have right now. Perhaps that's why the random biopsies have limited yield, if any.
The patients who have dysplastic lesions refracted or removed during the colonoscopy should have a higher risk of developing dysplasia or colon cancer. They should have at least 1 follow‑up colonoscopy within a short period of time, maybe within 6 months. If the capabilities are available, it should be with chromoendoscopy. If the subsequent surveillance colonoscopy with chromoendoscopy does not suggest any dysplasia, then those patients can go back to having annual surveillance procedures.
The last thing that I want to make a point about is that, patients who have unretractable dysplasia—whether the dysplasia is visible or not, but it is determined that it is not removable endoscopically—or those patients who have multifocal dysplasia are best referred to colectomy, because their risk of developing cancer is fairly high despite the use of surveillance.
Those are the few important take‑away points from my talk.
Amanda Balbi: Great. Thank you so much for talking to me today about your session.