Dr Coelho-Prabhu reviews the timing and techiques for surveillance of patients with inflammatory bowel disease for signs of colorectal cancer--and especially those with IBD and primary sclerosing cholangitis, which places them among those with highest risk of CRC. 

Nayantara Coelho-Prabhu, MD, is a professor of medicine at the Mayo Clinic in Rochester, Minnesota.

IBD Dysplasia Detection: Risk Assessment and Surveillance

• IBD carries twice the colon cancer risk of patients without IBD. Higher-risk features include primary sclerosing cholangitis (PSC), extensive colitis, severe inflammation, and prior dysplasia.
• Surveillance colonoscopy: Optimize bowel preparation, examine during endoscopic remission, and use high-definition imaging with dye or virtual chromoendoscopy; segmental reinspection is another option. Add four-quadrant random biopsies for PSC or prior dysplasia.
• Visible dysplasia: Consider advanced endoscopic resection. Follow-up ranges from 3–12 months after dysplasia resection and 1, 3, or 5 years without dysplasia. Examine ileal pouches with cuff biopsies every 1–3 years.

Hello, I'm Nayantara Coelho-Prabhu. I'm a professor of medicine at the Mayo Clinic in Rochester. And I'm here at the ACG this year to speak about dysplasia detection and surveillance in patients with IBD and IBD PSC, which is a higher risk group. So it's important to know that in the modern era, even though we have all these advanced therapeutics, colon cancer still occurs twice as often in patients with IBD than it does in patients without IBD. This includes both ulcerative colitis that extends beyond the rectum and Crohn's colitis. When you have patients that you identify as having high risk, then it is important to perform a high-quality colonoscopy.

So what are high risk patients? Well, these are classified as patients who have also got PSC in addition to IBD, if they have extensive disease, which involves a longer portion of their colon, and if they've had severe inflammation.

So important to remember that as your degree of inflammation is classified by the Mayo endoscopic score is higher, those patients' lifetime risk of cancer increases. Also, if they've had prior dysplasia, even if it's low grade, the data does suggest that they have an increased incidence moving forward of eventually developing cancer.

So now that you've identified the high-risk patients, what's the best way to do a colonoscopy? You really want to do a high quality colonoscopy when you perform IBD surveillance. This includes having as good a bowel preparation as the patient can manage, and then ideally performing this surveillance when patients are in endoscopic disease remission, which means they don't have significant disease activity. You also want to make sure that you use a high definition colonoscope, which is more than easily available nowadays.

And then the big question here that is always asked is what should I do to improve the imaging? And here the debate continues, but there are various options that you can do. So first of all, you use a high definition scope. You can consider dye chromoendoscopy, which is where you spray dye into the colon and examine on the way out. You can consider virtual chromoendoscopy, which is an electronic chromoendoscopy available on all your scopes, and depending on the scope manufacturer will be of various kinds. And the final option is one that was actually studied in a randomized control trial where they did high definition white light, but segmentally reinspected each segment of the colon. And so far the data suggests that as opposed to just a single pass high definition white light colonoscopy, both dye chromoendoscopy and virtual chromoendoscopy are recommended over the single pass white light. But this latest study, which shows that if you did high definition white light, but repeated and did two examinations of each segment of the colon, you might actually have as much dysplasia detected as if you did dye chromo.

So as our scopes get better and better and we have all of these new techniques to visualize the lining of the colon, my recommendation is to really use the technique that you are most familiar with. If you've been able to train with either dye chromoendoscopy or a particular kind of virtual chromoendoscopy, use that. Or if all you know is white light, do a thorough examination with a second look through each segment and your yield for detection of dysplasia will get better. Remember chromoendoscopy doesn't work well if there's significant inflammation or if the bowel prep isn't good. And so in those conditions, you want to avoid that. When should you do random biopsies? In the highest risk patients, all the guidelines still recommend doing four quadrant random biopsies. These are patients universally with PSC in addition to their IBD or if they have had prior dysplasia throughout the colon.

Now, once you find a lesion, use standardized descriptors to describe the lesion. Remember the five S's, describe the shape of the morphology using the Paris classification. Describe the site in the colon, the size, describe the surface pit pattern. If you can remember the Kudo classification, that's a good one to try. And then very importantly, describe the surrounding mucosa. Is there active inflammation? Is it scarred? Is it normal? All of these findings.

Now, once you found a lesion, what should you do about it? Well, increasingly IBD dysplasia can be resected by advanced endoscopic techniques, including EMR and ESD. And so you should consider referring your patients for these procedures if you find a visible lesion. If the patient has documented adenocarcinoma on the biopsies or there's significant submucosal fibrosis, or you really can't get the background mucosa to heal at all and there's ongoing active inflammation, those are patients that you might have to refer to colorectal surgery. And if you're not entirely certain, these can be referred to a specialist center where they can make that determination. Both EMR and ESD have been shown to be effective for IBD dysplasia. And so really you can refer the patients to your advanced endoscopist for this.

What about if you have invisible biopsies that show dysplasia? Well, in those cases, if the original study was done with high definition white light, the guidelines recommend a repeat procedure with dye chromoendoscopy and then deciding your interval based on what you find.

Once you've finished your surveillance colonoscopy, you now have the ability to tailor those follow-up procedures based on what you find. The guidelines clearly outline these follow-up intervals in terms of if you have resected dysplasia, you might bring the patient back anywhere from 3 to 12 months based on the pathology that you had. But if you have no dysplasia, then the change here is that you can start to tailor these guidelines to either 1, 3 or 5 years from that colonoscopy. And the best way to follow this is to read these most recent guidelines to suggest which interval.

Another quick reminder that in your patients who have ileal pouches, they still need to be surveyed for dysplasia in the rectal cuff. The guidelines suggest between 1 and 3 years, these should be examined with a pouchoscopy with cuff biopsies. So I hope eventually that we've convinced you that there are techniques to improve your endoscopic evaluation for dysplasia in IBD. Many of these are resectable and you want to make sure that you follow the surveillance intervals as recommended in the guidelines. Thank you.