To get us started, I'll be presenting on updates in colonoscopy surveillance. And this has to do with some of the indicators that I mentioned earlier. Very important to know. And there's been some recent updates in this. Here are my disclosures. So you see a 65-year-old male who comes for routine follow-up. And the patient reports that his last colonoscopy was three years ago. It was complete with good prep, and one tubular adenoma was removed. What is the best recommendation for this question? Please select one answer. Would you reassure him at this point that he's not due for another four to seven years, which would be seven to 10 years from his last exam? Would you order a colonoscopy because the patient is worried? Would you order an interval fit test or defer discussion of colon cancer screening or surveillance for one more year? So go ahead and vote, please. All right. So 61% said reassure and not due for another four to seven years. Very few were going to order another colonoscopy. Some individuals were interested in another fit or deferring the discussion. Excellent. This gives us a very nice framework for our talk. And before we proceed, I have another polling question for the audience. Now that everybody's had some coffee. So now your patient is a 50-year-old male who undergoes a multi-target stool DNA test. Cologuard is probably the one on the market, and it's positive. So it's followed by a complete colonoscopy. And you note that in the report, it says the Boston bowel prep was nine and the colonoscopy was normal and it was complete. However, the patient is concerned about the positive test. So what is the best option at this time for further management? Would you repeat the colonoscopy again? Would you perform a CT abdomen? Would you reassure the patient and repeat screening in 10 years? Or would you repeat the multi-target stool DNA test now? All right. So 57% would reassure and repeat in 10 years. And the next closest option is performing a CT abdomen. And repeating a colonoscopy or repeating the multi-stool DNA test kind of paired equal and towards the bottom. So excellent. We'll be addressing this also because it's becoming a pretty common scenario in practice. All right. So let's talk about the recently released recommendations for follow-up after colonoscopy and polypectomy. This is a guideline by the U.S. Multi-Society Task Force. And in full disclosure, myself and Dr. Jason Dominitz, who's also a course faculty and a speaker, are members of this task force. So before we launch into what it shows, I just wanted to go over some definitions that we'll be using as we talk about these new recommendations. When we say somebody with a low-risk adenoma or a non-advanced adenoma, what that generally refers to is one to two tubular adenomas that are small, i.e., less than 10 millimeters in size. An advanced adenoma is 10 millimeters or larger or may have villus features or high-grade dysplasia. When we talk about advanced neoplasia, it's combining advanced adenoma and colon cancers. A low-risk adenoma is advanced neoplasia or three or more adenomas of any size. A sessile serrated adenoma or polyp is one that's defined histologically. And a serrated polyp is either a SSA slash P or a hyperplastic polyp or SSL, as we now call them. So I'll mainly be focusing on these two categories. This is probably the bulk of what we see in practice. And this is truly where the guidelines have made changes. And here are the changes. I'll lay them out front, and then we'll discuss them. So for individuals with one to two small tubular adenomas, the new recommended interval for repeat surveillance colonoscopy is seven to 10 years. We thought, and it's a strong recommendation because we found moderate quality of evidence. For individuals with three to four tubular adenomas that are small, again, the recommended interval is three to five years. So this used to be three years. We put in some wiggle room and made it three to five years. Again, the strength of recommendation is weak, and quality of evidence was very low. And the other recommendations are, as you can see, but they didn't change very much. And in practice, the bulk of the patients that undergo screening colonoscopy will likely have normal findings. That's where we recommend a 10-year follow-up interval, and that recommendation did not change. However, 30 to 40% of our colonoscopy practice will have patients with these two findings, and that's where the guidelines have lengthened. And then 5% to 10% of patients that undergo screening colonoscopy have some of these other more, either more tubular adenomas or more advanced, and you can see the recommendations there range from six months to three years, depending on the finding. So let's talk about low-risk adenomas. This is the bulk of what we find in colonoscopy. The Multi-Society Task Force recommends repeat colonoscopy in seven to 10 years instead of five to 10 for patients with one to two small tubular adenomas. And this is based on good evidence that tells us that there's a similar colon cancer risk for these individuals compared to individuals having a normal colonoscopy. And in fact, some studies indicated that their risk of colon cancer is actually lower than the general population. Now, that's a head scratcher. You might wonder why that is. It's because the general population is kind of a mixed bag. These are individuals that have had screening or not had screening and have a variety of degrees of high-risk features. But if somebody undergoes a colonoscopy and all they have is low-risk adenomas, they're earmarked for having a lower risk than the general population, which is a mixture of a combination of risks. And again, there's multiple studies to support these recommendations. So this was a very large meta-analysis with eight studies and 10,000 patients where you can see the authors compared individuals with no adenomas, low-risk adenomas, or advanced adenomas for risk of subsequent advanced neoplasia on future surveillance. And you can see the low-risk adenoma was very similar to the no adenoma group at baseline. And the advanced adenoma group truly kind of separates out from this. Here are two more studies that show that low-risk adenoma is associated with a reduced risk of not just developing colon cancer, but from fatal colon cancer. The first one on the top right of your screen very nicely shows follow-up of individuals with no adenoma shown in orange, non-advanced adenomas in blue, and advanced adenomas in dark blue. And you can see that the non-advanced adenoma and the no adenoma lines pretty much overlap for 15 years of follow-up, and this is for colon cancer incidence, such that there's no difference between the colon cancer incidence for these two groups. And then in the bottom graph, you can see the risk of fatal colon cancers among the general population compared to individuals with a low-risk adenoma and those with a high-risk adenoma. And you can see the low-risk adenoma group is actually even at lower risk of dying from colon cancer compared to the general population, suggesting that these are individuals that we can pretty much earmark as not being at high risk for progression. So why did we change the three-year interval to five-year interval for individuals with three to four small adenomas? And the reason is that, you know, with our focus on adenoma detection and increasing identification, we are finding more and more patients with three to small tubular adenomas. So say 10 years ago, these would be individuals where we would find maybe one adenoma. But because of our high-def equipment, high magnification, good prep, and emphasis on adequate withdrawal, we're finding a lot of small adenomas in these individuals. And that almost creates a paradox because these individuals have a lower risk of colon cancer because, one, we examine them so thoroughly, and second, because we bring them at such aggressive surveillance interval of three years, that their risk is actually lower than the risk of the general population or individuals with no findings. And there are several studies also where they teased out the number of adenomas that very nicely showed that individuals that have three to four adenomas behave very similar to individuals with one to two adenomas. And as we discussed previously, they're now considered at lower risk than we previously thought. And you can also see that not only do they have lower risk of advanced neoplasia at the next surveillance colonoscopy, but the rate of incident colon cancer in follow-up is much lower in individuals with three to four small to big adenomas. Hence we were comfortable shifting their follow-up to three to five years instead of three years as previously. So not only did we give recommendations on when the follow-up should be for the first colonoscopy after the index one, but also what should happen at the next surveillance based on the baseline findings. So you can see in the first column on the left are baseline findings and the recommended interval for the first surveillance. However, when those individuals come back, depending on the finding at the second colonoscopy, we can actually change the interval and most of it gets lengthened. So for instance, individuals with one to two small tubular adenomas, we bring them back in seven years, now they have a normal colonoscopy. Those individuals can be followed up in 10 years for their next exam. Similarly, individuals with three to four tubular adenomas that are small, we give them a three to five year pass, they come back on their next colonoscopy, there are no findings. Or there are one to two small tubular adenomas, well, we can give them a seven to 10 year pass. So what this suggests is that the most recent colonoscopy kind of dictates future surveillance intervals, such that even individuals with advanced adenomas or more than five that we were following every three years, well, now if they have a normal colonoscopy, they can come back in five years from then on. So this really helps us frame the risk to the patients, because again, undergoing repeat surveillance colonoscopy is protective and reduces their risk of subsequent neoplasia. So here are the recommendations summarized again, the caveat here is that the colonoscopy needs to be a high quality colonoscopy defined as complete to the cecum, adequate bowel prep to detect polyps at least five millimeters or larger, have been done by a colonoscopist with adequate ADR, and any polyps that were found were completely removed. If those conditions are met, then you can see that we can risk stratify individuals for repeat colonoscopy to anywhere between one year for individuals with more than 10 adenomas, three years if they have five to 10 adenomas, three to five years for individuals with three to four adenomas, seven to 10 years for one to two adenomas or 10 years for a normal colonoscopy. Notice that for SSPs, we gave a five to 10 year interval, and I'll address that shortly. So first, why give a range? Why use seven to 10 instead of either seven or eight or nine or just 10? Well, there were several considerations here. So one is that giving a range is potentially confusing to primary care physicians, colonoscopies and patients. It's really hard to put in an automated recall system, a range. So you really have to pick something. And we figured most individuals may err to the side of the shorter interval, which is seven years. Well, the advantages of having a range is that it can indicate where longer polyps surveillance might be supported by emerging evidence. There might be certain features that might tip us towards seven instead of 10, and that's totally fine. The range allows clinicians to consider available evidence and also patients' comfort level, their value and preferences in where the surveillance interval should fall. And it really gives an opportunity for shared decision making. And what that might look like is, so for instance, patients with excellent PrEP, only two small tubular adenomas that might even be diminutive. You might give them a 10 year pass, however, individuals with small adenomas who at a five year follow up with more small adenomas, and you might be more comfortable with a seven year interval in that scenario. So it gives us some nice wiggle room. So again, the largest change in the new surveillance guidelines is these two categories, one to two small tubular adenomas, seven to 10 years, and three to four small tubular adenomas, three to five years. All right. So most of you got this answer correct. Our 65 year old who wanted to know when he was due again, you would, based on what we just talked about, you would reassure him that he's not due for four to seven years, which would be seven to 10 years after his last exam. And this is evidence-based and congruent with guideline recommendations. A word on serrated polyps, when should their follow up colonoscopy be? So there's much lower level of evidence for sessile serrated polyps. As we all know, they were more recently described. There's differences in how they're histologically characterized across studies. So we decided to take a more cautious approach. The available data suggests that having an SSP increases risk for future serrated polyps more so than future colon cancer. And the increased risk for high risk adenomas is mainly seen when an SSP is found with a conventional adenoma. However, these lesions do tend to be more difficult to recognize, and there's more challenges in figuring out where the borders are and a higher risk of incomplete resection. But the question is, are serrated polyps bad players like we initially thought? Well, this one study very nicely separated out the risk of serrated polyps by also their number. And you can see that compared to individuals with no polyps, individuals with one to two serrated polyps or serrated polyps smaller than 10 millimeters had a very similar risk of developing colon cancer at five years or 10 years after the index colonoscopy. And when the serrated polyps were large, 10 millimeters or larger, then you can start seeing the risk of colon cancer start to creep up. And when advanced adenomas were found, the risk was probably the highest in terms of future colon cancer incidents. So this tells us that they fall somewhere closer to tubular adenomas when they're small. And when they start getting larger, they start to approach the risk of advanced adenomas. So surveillance recommendations for serrated polyps are for individuals with one to two sessile serrated polyps smaller than 10 millimeters, five to 10 years is the recommended interval. And the reason for that is, again, the level of evidence just wasn't there. So we were more comfortable giving it a five to 10 instead of a seven to 10. So again, these are the findings at the first colonoscopy and what the recommended interval should be at the next colonoscopy. So our case two, which is a common scenario in practice as these multi-target stool DNA tests become more common screening modality, was individuals that have a false positive stool DNA test. That is the multi-target stool DNA test is positive, but the complete colonoscopy doesn't find anything. The recommended interval in this scenario is truly to just give them a normal interval. And basically, the findings of the colonoscopy then dictate the next screening. So let's talk a little bit about this multi-target stool DNA test. This was a landmark study in 2014, which compared a one-time multi-target stool DNA test to a one-time fit test. And you can see that it had higher sensitivity for detecting colon cancer, but lower specificity, which means that there were more false positives. However, the sensitivity for detecting advanced adenomas was still not very high, 42 percent compared to 23 percent for fit. The limitations of the study was only a one-time test was studied. The repeat interval is not known. Many individuals fail to complete the stool DNA test because it requires a complex collection of not just the fit portion, but also collecting the stool in a big jar and mailing that in. Programmatic effectiveness is not known. And we don't have yet great evidence on whether the screening modality reduces colon cancer incidence or mortality. The cost effectiveness is debated. The test costs approximately $600 compared to approximately $22 for the fit test. And then there's concerns about the false positive test, which can lead to over-testing, over-diagnosis, and harms associated with it. So, what should happen with a false positive stool DNA test? So, that scenario where the stool DNA test is positive, but the colonoscopy doesn't find anything. Well, there's multiple studies that have now informed this issue. This was one of the largest ones with 10,000 patients who had a stool DNA test, and then they were followed for the next four years. There were eight cancers diagnosed, and you can see they're a mixture of different GI cancers. However, the important thing is that there was no difference in those that tested positive versus negative on the initial stool DNA test for future cancer risk. And another larger study was done on 1,200 subjects who had a negative colonoscopy. And the median follow-up in this case was over five years. The concordant group was individuals that had a negative stool DNA test and a negative colonoscopy. And amongst these individuals, 11 cancers were found. You can see the distribution. And the discordant group was where the stool DNA test was positive, but the colonoscopy was negative. And five cancers were found in this group. And you can see the smattering. The risk ratio was not significant. So the conclusion was that no further workup is required for a positive test after the negative colonoscopy. So I'll summarize the take-home points. Surveillance colonoscopy in appropriate individuals is high-value care. New evidence shows that one to two small adenomas or SSPs have similar outcomes as normal colonoscopy. New follow-up colonoscopy intervals have been lengthened, particularly for these lower risk adenomas. Surveillance has been extended to seven to 10 years for one to two small adenomas and three to five years for three to four small adenomas. And future surveillance lengthened, may be lengthened based on the first surveillance colonoscopy findings. A false positive ColoGuard test does not need any special follow-up and screening should be repeated in 10 years after negative colonoscopy.

colonoscopy surveillance

recommendations

follow-up

tubular adenomas

serrated polyps

evidence-based