15 Need-to-Know Presentations From DDW 2021

David A. Johnson, MD


May 26, 2021

This transcript has been edited for clarity.

Hello. I'm Dr David Johnson, professor of medicine and chief of gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia.

Although Digestive Disease Week 2021 was held virtually, that certainly didn't mean it was lacking in great science to report.

After going through this year's presentations, I wanted to give you my overview on those that I consider among the best, some with results that are actionable now and others whose impact may be felt farther away on the horizon.

Detecting Colorectal Cancer: How and Where

The first pair of studies come from Dr Joseph Anderson's group at Dartmouth College, using data from the New Hampshire Colonoscopy Registry.

The first study[1] compared the results of patients who underwent colonoscopy after having a positive fecal immunochemical test (FIT) or multitarget stool DNA (mt-sDNA) screening test, to those who underwent colonoscopy without such a preceding test. The investigators noted that patients with a positive mt-sDNA had a substantially higher yield of colorectal neoplasia than those with a positive FIT (67% vs 44%, respectively; P < .001).

The 2021 guidelines on colorectal cancer screening from the American College of Gastroenterology, which I recently reviewed, actually recommend minimum acceptable thresholds for adenoma detection rates in FIT-positive populations of 45% in men and 35% in women. This study suggests even higher rates for mt-sDNA, largely due to the increased yield of the serrated polyps, which the FIT obviously doesn't catch. Therefore, we must consider raising our expectations for FIT-positive patients as well as looking for serrated lesions in mt-sDNA-positive patients.

In the second study of data from this registry,[2] investigators focused on colorectal neoplasia in younger patients. This is in line with just-released guidelines from the US Preventive Services Task Force that recommend beginning colorectal cancer screening at age 45, which itself is in concert with recommendations from other societies.

The investigators looked at 17,000 average-risk patients with adenomas and found that patients younger than 44 years were significantly more likely to have left-sided advanced lesions when compared with the other cohorts of 45- to 60-plus years (approximately 59% vs 46%-53%, respectively).

This striking result reflects what we've seen elsewhere in the literature, that there is a leftward shift for colorectal lesions in younger patients, in particular favoring the rectal area. It means that we should consider looking at left-side lesions among high-risk younger patients, as that's where the biologic evidence suggests these earlier lesions are predominately appearing.

Two Studies on Vedolizumab and Infliximab

A multicenter study[3] assessed the efficacy and safety of vedolizumab and infliximab for immune checkpoint inhibitor–induced colitis and diarrhea. Current treatment guidelines for these patients suggest the use of steroids and then selective immunosuppressive therapy, including infliximab or vedolizumab, for refractory cases.

After analyzing 184 patients, investigators found that vedolizumab and infliximab led to comparable rates of response (89% vs 88%, respectively). However, the vedolizumab group experienced a shorter duration of median hospital stay (10.5 days vs 13.5 days) and fewer hospitalizations (16% vs 28%). Vedolizumab alone was associated with better overall survival (P = .027), which you would expect in patients with cancer. Overall, you may want to consider these results as you move forward in your treatment of these patients, who we're seeing more and more of in our clinical practice.

A separate study,[4] primarily conducted in Denmark, looked at the issue of discontinuing infliximab if you have a patient with Crohn's disease. This is the first randomized, double-blind, placebo-controlled trial on withdrawal in Crohn's disease. All 115 patients who were entered into the study were considered to be in complete remission, with normal Crohn's Disease Activity Index scores at 1 year. They were then randomized to withdrawal or continued use of infliximab.

Lo and behold, investigators found that there was a considerable risk for relapse, despite the fact that they were in complete remission going into the trial. The significant risk reduction was particularly evident in the infliximab group, 96% of whom were still in remission at the trial's end compared with 49% in the placebo group.

These results indicate that when you have a good thing going, don't stop continuing on that course of infliximab, and certainly not after a year.

Targeting Sedentary Lifestyles in Those With Hepatic Steatosis

A study on patients with nonalcoholic fatty liver disease (NAFLD) caught my eye given its simple and easy-to-understand implications.[5] We know that patients with NAFLD have coincident diseases and comorbidities related to cardiovascular disease. Investigators looked at nearly 1000 patients with hepatic steatosis who were assessed for the presence of other risk factors, in particular for coronary artery disease and predictors of incident major adverse cardiovascular events.

Unsurprisingly, they showed that lipids and higher B-type natriuretic peptide were independently associated with coronary artery disease.

But what really jumped out at me was the suggestion that a sedentary lifestyle increased the risk for these major adverse coronary events by twofold. Sedentary lifestyle is modifiable and something we can target when discussing risk-reduction strategies with our patients with NAFLD.

The 'Cold Snare Revolution' Continues

There was also more compelling evidence on the so-called cold snare revolution in polypectomy.

Investigators behind a randomized multicenter study from Taiwan[6] looked at 4270 patients with polyps that were 4-10 mm. They showed that there was a significant risk reduction in delayed bleeding among patients who underwent cold snare vs hot snare polypectomy (0.4% vs 1.5%, respectively). There was no difference between the polypectomy methods as it related to the rate of tissue retrieval or en bloc resection.

These results show once again that cold snare is the way to go and should be considered the standard of care for small polyps of 4-10 mm.

Reducing Costs and Delays With Endoscopy

There were two studies that should be of interest to those in hospital systems with an eye to inpatient costs and delays associated with endoscopy, both of which came from researchers at the University of Florida, Gainesville.

The first study[7] related to length of stay. Investigators conducted a data analysis of nearly 4300 patients who underwent endoscopy over a 2-year period at a tertiary care referral center. They found that approximately 19% of these patients had experienced a delay, the most common causes of which were poor bowel preparation (27%) and lack of endoscopy personnel or unit availability (24%), which may include anesthesia. These delays equated to approximately two additional inpatient days at a cost of around $1300 a day.

In the second study,[8] the researchers looked at the same population and found that these delays led to a significant increase in patients readmitted within 30 days.

Such delays have a significant impact on costs, but their causes are certainly modifiable. Your hospital systems will light up when you say, "I think we can do better." These results show that can be achieved by getting adequate preparations and becoming more time-efficient with endoscopies.

Measuring Radiation Exposure During Endoscopic Procedures

Ionizing radiation is an established carcinogen, which is why I took note of the results of a study from Johns Hopkins Medicine.

Researchers retrospectively assessed the effects of low-dose radiation over a number of years among 352 patients who underwent at least one endoscopic procedure.[9] They measured radiation exposure per endoscopic event in milligrays (mGy).

They found that patients were exposed to a cumulative median radiation dose of approximately 18 mGy. This is an important number to consider because it's far greater than the exposure rates reported from radiation safety workers and even from some of the Nagasaki and Hiroshima bomb follow-up data, which are closer to a threshold of 5 mGy.

It's also important to remember that these were one-time procedures for the majority of patients. We need to be cautious about radiation exposure from multiple procedures, particularly among younger patients. This is now a well-recognized risk, with a number of publications linking low-dose radiation to excess cancer. We need to do better and certainly need to be tracking this in our patients.

Simple Counseling Reduces Perianal Disease During Pregnancy

The next study[10] stands out for offering a relatively straightforward intervention. It's also the first time I've ever seen a randomized controlled trial on the topic of hemorrhoids and fissures in pregnancy.

Researchers randomized 260 women during the first trimester of their pregnancies to dietary and behavior interventions, aimed at preventing constipation and prolonged straining, and reducing time on the commode, or to routine pre- and perinatal care.

They found that only 20% of pregnant women who received [dietary and behavior] counseling had postnatal perianal disease, hemorrhoids, or fissures, as opposed to 48% of those who received routine obstetric care.

Counseling of this type represents an easy intervention that doesn't cost anything to speak of. I'm going to prioritize this with our patients who are pregnant. I also wanted to share this information with our colleagues in obstetrics and gynecology to use in their practice.

A New Standard in Zenker's Diverticulum

Peroral endoscopic myotomy (POEM) is an emerging standard technique that we are taking over more often from our otolaryngologist (or ENT) colleagues.

This multicenter international trial[11] suggests that POEM is a technique that we may want to apply for Zenker's diverticulum. Researchers indicated that they achieved a 100% rate of technical success using POEM in this indication instead of standard septotomy. Use of POEM led to no significant adverse events, whereas there was a 21% rate of adverse events in the septotomy group. POEM took an average of 42 minutes to conduct.

These results provide more evidence that POEM is something that interventional endoscopists can be doing routinely, and I think it may become the standard of care in Zenker's diverticulum.

The Upsides of a 'Squatty Potty'

Many of you may have heard of the so-called Squatty Potty, which is used to modify positions (ie, lifting the feet up) to improve defecation.

In this study from the University of Michigan,[12] researchers tested its impact on positional effects during a balloon expulsion test. They were able to show that this defecation posture–modifying device led to a normalization of the balloon expulsion in about 1 out of 7 patients with chronic constipation.

This is a very simple device to use.

I plan on sharing these results with our pelvic floor group and anal rectal motility analysis technicians and ask them to start doing positional measures in these patients. It may provide the means to allow for a simple targeted treatment recommendation when you're doing these balloon expulsion tests.

Strategies for Patients With Cirrhosis Who Have Acute Cholecystitis

Often, surgeons will not want to take on a severely sick patient with cirrhosis who has acute cholecystitis. These high-risk patients were the focus of a multicenter comparative trial.[13] Sixty-three patients with cirrhosis considered unfit for surgery underwent gallbladder drainage using a percutaneous cholecystostomy (PC) tube or endoscopic ultrasound-guided gallbladder drainage (EGBD) using lumen apposing metal stents.

Researchers reported a technical success rate of 95% and 100% in the PC and EGBD groups, respectively, indicating a comparable ability to deliver the two treatments. However, the incidence of adverse events was significantly elevated by nearly 35% in patients with higher Child-Pugh scores. In fact, additional surgical intervention was required in a significantly greater portion of patients in the PC group than in the EGBD group (28% vs 5%, respectively).

It appears that EGBD with lumen-apposing metal stents is an effective and safe alternative to PC.

This suggests a role for interventional endoscopists in performing EGBD, which is something that I think your surgeons will appreciate because it keeps these high-risk patients from the operating room.

New Treatments on the Horizon

I wanted to mention two promising studies whose results may be impactful in the future.

The first is a phase 3 trial of risankizumab,[14] a monoclonal antibody against interleukin-23, a key cytokine in the pathogenesis of inflammatory bowel disease. Previous phase 2 studies suggested that very favorable results could be achieved with this treatment, marking it as potentially playing a very significant role in the coming years.

Researchers studied the use of this therapy in moderate to severe Crohn's disease with intolerance or inadequate response to conventional or biologic therapy. Although this is a tough patient group to take on, they nonetheless showed a significant improvement after treatment with both 600-mg and 1200-mg doses. At week 12, both doses showed a comparable level of response, and far better than the placebo as it relates to the primary endpoint of remission determined by the Crohn's Disease Activity Index score (45% for 600 mg and 42% for 1200 mg vs 25% for placebo), with a similar trend on display for endoscopic response. Notably, active tuberculosis was reported in one patient with a previous history of it, which is something that we need to be aware of in this population.

However, risankizumab seems to be much more effective than placebo in this target group of difficult-to-treat patients with previous failure to respond. Stay tuned, as I'm sure we'll be seeing more about this treatment soon.

The final study[15] I'd like to discuss related to the use of artificial intelligence (AI). We've seen a lot of research with AI for colon polyps and colorectal neoplasia, as well as a bit in inflammatory bowel disease.

This study from the University of California–Irvine comes from a team of researchers who have really been leading the way in applying AI to identifying dysplastic lesions in Barrett's esophagus. They performed an external validation study that showed really strong promise for this indication, with a 100% negative predictive value and a 2.4% false positivity for dysplasia.

I think this is more evidence that AI technology may be available over the short-term horizon and that now applies to Barrett's esophagus as well. Stay tuned, as there's surely more to come.

Hopefully, these studies have piqued your interest. Their results have game-changing implications for your practices today and potentially further along on the horizon. We'll obviously look forward to the publications to corroborate the data presented. In the meantime, I recommend you review the abstracts of most interest to you.

As always, thank you for listening. I'm Dr David Johnson. See you next time.

David A. Johnson, MD, a regular contributor to Medscape, is professor of medicine and chief of gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia, and a past president of the American College of Gastroenterology. His primary focus is the clinical practice of gastroenterology. He has published extensively in the internal medicine/gastroenterology literature, with principal research interests in esophageal and colon disease, and more recently in sleep and microbiome effects on gastrointestinal health and disease.

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